October 2024 - Linux-stable-mirror

FAILED: patch "[PATCH] padata: use integer wrap around to prevent deadlock on seq_nr" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 9a22b2812393d93d84358a760c347c21939029a6 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100110-smokiness-detract-b410@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: 9a22b2812393 ("padata: use integer wrap around to prevent deadlock on seq_nr overflow") 57ddfecc72a6 ("padata: Fix list iterator in padata_do_serial()") f601c725a6ac ("padata: remove padata_parallel_queue") 4611ce224688 ("padata: allocate work structures for parallel jobs from a pool") f1b192b117cd ("padata: initialize earlier") 305dacf77952 ("padata: remove exit routine") bfcdcef8c8e3 ("padata: update documentation") 3facced7aeed ("padata: remove reorder_objects") 91a71d612128 ("padata: remove cpumask change notifier") 894c9ef9780c ("padata: validate cpumask without removed CPU during offline") bbefa1dd6a6d ("crypto: pcrypt - Avoid deadlock by using per-instance padata queues") 07928d9bfc81 ("padata: Remove broken queue flushing") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 9a22b2812393d93d84358a760c347c21939029a6 Mon Sep 17 00:00:00 2001 From: VanGiang Nguyen <vangiang.nguyen(a)rohde-schwarz.com> Date: Fri, 9 Aug 2024 06:21:42 +0000 Subject: [PATCH] padata: use integer wrap around to prevent deadlock on seq_nr overflow When submitting more than 2^32 padata objects to padata_do_serial, the current sorting implementation incorrectly sorts padata objects with overflowed seq_nr, causing them to be placed before existing objects in the reorder list. This leads to a deadlock in the serialization process as padata_find_next cannot match padata->seq_nr and pd->processed because the padata instance with overflowed seq_nr will be selected next. To fix this, we use an unsigned integer wrap around to correctly sort padata objects in scenarios with integer overflow. Fixes: bfde23ce200e ("padata: unbind parallel jobs from specific CPUs") Cc: <stable(a)vger.kernel.org> Co-developed-by: Christian Gafert <christian.gafert(a)rohde-schwarz.com> Signed-off-by: Christian Gafert <christian.gafert(a)rohde-schwarz.com> Co-developed-by: Max Ferger <max.ferger(a)rohde-schwarz.com> Signed-off-by: Max Ferger <max.ferger(a)rohde-schwarz.com> Signed-off-by: Van Giang Nguyen <vangiang.nguyen(a)rohde-schwarz.com> Acked-by: Daniel Jordan <daniel.m.jordan(a)oracle.com> Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au> diff --git a/kernel/padata.c b/kernel/padata.c index 53f4bc912712..222bccd0c96b 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -404,7 +404,8 @@ void padata_do_serial(struct padata_priv *padata) /* Sort in ascending order of sequence number. */ list_for_each_prev(pos, &reorder->list) { cur = list_entry(pos, struct padata_priv, list); - if (cur->seq_nr < padata->seq_nr) + /* Compare by difference to consider integer wrap around */ + if ((signed int)(cur->seq_nr - padata->seq_nr) < 0) break; } list_add(&padata->list, pos);

7 months, 1 week

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FAILED: patch "[PATCH] cpuidle: riscv-sbi: Use scoped device node handling to fix" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x a309320ddbac6b1583224fcb6bacd424bcf8637f # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100154-maternity-snowfield-cbf4@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: a309320ddbac ("cpuidle: riscv-sbi: Use scoped device node handling to fix missing of_node_put") 24760e43c6a6 ("cpuidle: Adjust includes to remove of_device.h") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From a309320ddbac6b1583224fcb6bacd424bcf8637f Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski <krzysztof.kozlowski(a)linaro.org> Date: Tue, 20 Aug 2024 11:40:22 +0200 Subject: [PATCH] cpuidle: riscv-sbi: Use scoped device node handling to fix missing of_node_put Two return statements in sbi_cpuidle_dt_init_states() did not drop the OF node reference count. Solve the issue and simplify entire error handling with scoped/cleanup.h. Fixes: 6abf32f1d9c5 ("cpuidle: Add RISC-V SBI CPU idle driver") Cc: All applicable <stable(a)vger.kernel.org> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski(a)linaro.org> Reviewed-by: Anup Patel <anup(a)brainfault.org> Link: https://patch.msgid.link/20240820094023.61155-1-krzysztof.kozlowski@linaro.… Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com> diff --git a/drivers/cpuidle/cpuidle-riscv-sbi.c b/drivers/cpuidle/cpuidle-riscv-sbi.c index a6e123dfe394..5bb3401220d2 100644 --- a/drivers/cpuidle/cpuidle-riscv-sbi.c +++ b/drivers/cpuidle/cpuidle-riscv-sbi.c @@ -8,6 +8,7 @@ #define pr_fmt(fmt) "cpuidle-riscv-sbi: " fmt +#include <linux/cleanup.h> #include <linux/cpuhotplug.h> #include <linux/cpuidle.h> #include <linux/cpumask.h> @@ -236,19 +237,16 @@ static int sbi_cpuidle_dt_init_states(struct device *dev, { struct sbi_cpuidle_data *data = per_cpu_ptr(&sbi_cpuidle_data, cpu); struct device_node *state_node; - struct device_node *cpu_node; u32 *states; int i, ret; - cpu_node = of_cpu_device_node_get(cpu); + struct device_node *cpu_node __free(device_node) = of_cpu_device_node_get(cpu); if (!cpu_node) return -ENODEV; states = devm_kcalloc(dev, state_count, sizeof(*states), GFP_KERNEL); - if (!states) { - ret = -ENOMEM; - goto fail; - } + if (!states) + return -ENOMEM; /* Parse SBI specific details from state DT nodes */ for (i = 1; i < state_count; i++) { @@ -264,10 +262,8 @@ static int sbi_cpuidle_dt_init_states(struct device *dev, pr_debug("sbi-state %#x index %d\n", states[i], i); } - if (i != state_count) { - ret = -ENODEV; - goto fail; - } + if (i != state_count) + return -ENODEV; /* Initialize optional data, used for the hierarchical topology. */ ret = sbi_dt_cpu_init_topology(drv, data, state_count, cpu); @@ -277,10 +273,7 @@ static int sbi_cpuidle_dt_init_states(struct device *dev, /* Store states in the per-cpu struct. */ data->states = states; -fail: - of_node_put(cpu_node); - - return ret; + return 0; } static void sbi_cpuidle_deinit_cpu(int cpu)

7 months, 1 week

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FAILED: patch "[PATCH] icmp: change the order of rate limits" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y git checkout FETCH_HEAD git cherry-pick -x 8c2bd38b95f75f3d2a08c93e35303e26d480d24e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100131-unfixed-excursion-b8a2@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^.. Possible dependencies: 8c2bd38b95f7 ("icmp: change the order of rate limits") d0941130c935 ("icmp: Add counters for rate limits") 8032bf1233a7 ("treewide: use get_random_u32_below() instead of deprecated function") c5f0a1728874 ("rhashtable: make test actually random") 197173db990c ("treewide: use get_random_bytes() when possible") a251c17aa558 ("treewide: use get_random_u32() when possible") 7e3cf0843fe5 ("treewide: use get_random_{u8,u16}() when possible, part 1") 8b3ccbc1f1f9 ("treewide: use prandom_u32_max() when possible, part 2") 81895a65ec63 ("treewide: use prandom_u32_max() when possible, part 1") 27bc50fc9064 ("Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 8c2bd38b95f75f3d2a08c93e35303e26d480d24e Mon Sep 17 00:00:00 2001 From: Eric Dumazet <edumazet(a)google.com> Date: Thu, 29 Aug 2024 14:46:39 +0000 Subject: [PATCH] icmp: change the order of rate limits ICMP messages are ratelimited : After the blamed commits, the two rate limiters are applied in this order: 1) host wide ratelimit (icmp_global_allow()) 2) Per destination ratelimit (inetpeer based) In order to avoid side-channels attacks, we need to apply the per destination check first. This patch makes the following change : 1) icmp_global_allow() checks if the host wide limit is reached. But credits are not yet consumed. This is deferred to 3) 2) The per destination limit is checked/updated. This might add a new node in inetpeer tree. 3) icmp_global_consume() consumes tokens if prior operations succeeded. This means that host wide ratelimit is still effective in keeping inetpeer tree small even under DDOS. As a bonus, I removed icmp_global.lock as the fast path can use a lock-free operation. Fixes: c0303efeab73 ("net: reduce cycles spend on ICMP replies that gets rate limited") Fixes: 4cdf507d5452 ("icmp: add a global rate limitation") Reported-by: Keyu Man <keyu.man(a)email.ucr.edu> Signed-off-by: Eric Dumazet <edumazet(a)google.com> Reviewed-by: David Ahern <dsahern(a)kernel.org> Cc: Jesper Dangaard Brouer <hawk(a)kernel.org> Cc: stable(a)vger.kernel.org Link: https://patch.msgid.link/20240829144641.3880376-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> diff --git a/include/net/ip.h b/include/net/ip.h index c5606cadb1a5..82248813619e 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -795,6 +795,8 @@ static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb) } bool icmp_global_allow(void); +void icmp_global_consume(void); + extern int sysctl_icmp_msgs_per_sec; extern int sysctl_icmp_msgs_burst; diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index b8f56d03fcbb..0078e8fb2e86 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -224,57 +224,59 @@ int sysctl_icmp_msgs_per_sec __read_mostly = 1000; int sysctl_icmp_msgs_burst __read_mostly = 50; static struct { - spinlock_t lock; - u32 credit; + atomic_t credit; u32 stamp; -} icmp_global = { - .lock = __SPIN_LOCK_UNLOCKED(icmp_global.lock), -}; +} icmp_global; /** * icmp_global_allow - Are we allowed to send one more ICMP message ? * * Uses a token bucket to limit our ICMP messages to ~sysctl_icmp_msgs_per_sec. * Returns false if we reached the limit and can not send another packet. - * Note: called with BH disabled + * Works in tandem with icmp_global_consume(). */ bool icmp_global_allow(void) { - u32 credit, delta, incr = 0, now = (u32)jiffies; - bool rc = false; + u32 delta, now, oldstamp; + int incr, new, old; - /* Check if token bucket is empty and cannot be refilled - * without taking the spinlock. The READ_ONCE() are paired - * with the following WRITE_ONCE() in this same function. + /* Note: many cpus could find this condition true. + * Then later icmp_global_consume() could consume more credits, + * this is an acceptable race. */ - if (!READ_ONCE(icmp_global.credit)) { - delta = min_t(u32, now - READ_ONCE(icmp_global.stamp), HZ); - if (delta < HZ / 50) - return false; - } + if (atomic_read(&icmp_global.credit) > 0) + return true; - spin_lock(&icmp_global.lock); - delta = min_t(u32, now - icmp_global.stamp, HZ); - if (delta >= HZ / 50) { - incr = READ_ONCE(sysctl_icmp_msgs_per_sec) * delta / HZ; - if (incr) - WRITE_ONCE(icmp_global.stamp, now); + now = jiffies; + oldstamp = READ_ONCE(icmp_global.stamp); + delta = min_t(u32, now - oldstamp, HZ); + if (delta < HZ / 50) + return false; + + incr = READ_ONCE(sysctl_icmp_msgs_per_sec) * delta / HZ; + if (!incr) + return false; + + if (cmpxchg(&icmp_global.stamp, oldstamp, now) == oldstamp) { + old = atomic_read(&icmp_global.credit); + do { + new = min(old + incr, READ_ONCE(sysctl_icmp_msgs_burst)); + } while (!atomic_try_cmpxchg(&icmp_global.credit, &old, new)); } - credit = min_t(u32, icmp_global.credit + incr, - READ_ONCE(sysctl_icmp_msgs_burst)); - if (credit) { - /* We want to use a credit of one in average, but need to randomize - * it for security reasons. - */ - credit = max_t(int, credit - get_random_u32_below(3), 0); - rc = true; - } - WRITE_ONCE(icmp_global.credit, credit); - spin_unlock(&icmp_global.lock); - return rc; + return true; } EXPORT_SYMBOL(icmp_global_allow); +void icmp_global_consume(void) +{ + int credits = get_random_u32_below(3); + + /* Note: this might make icmp_global.credit negative. */ + if (credits) + atomic_sub(credits, &icmp_global.credit); +} +EXPORT_SYMBOL(icmp_global_consume); + static bool icmpv4_mask_allow(struct net *net, int type, int code) { if (type > NR_ICMP_TYPES) @@ -291,14 +293,16 @@ static bool icmpv4_mask_allow(struct net *net, int type, int code) return false; } -static bool icmpv4_global_allow(struct net *net, int type, int code) +static bool icmpv4_global_allow(struct net *net, int type, int code, + bool *apply_ratelimit) { if (icmpv4_mask_allow(net, type, code)) return true; - if (icmp_global_allow()) + if (icmp_global_allow()) { + *apply_ratelimit = true; return true; - + } __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITGLOBAL); return false; } @@ -308,15 +312,16 @@ static bool icmpv4_global_allow(struct net *net, int type, int code) */ static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt, - struct flowi4 *fl4, int type, int code) + struct flowi4 *fl4, int type, int code, + bool apply_ratelimit) { struct dst_entry *dst = &rt->dst; struct inet_peer *peer; bool rc = true; int vif; - if (icmpv4_mask_allow(net, type, code)) - goto out; + if (!apply_ratelimit) + return true; /* No rate limit on loopback */ if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) @@ -331,6 +336,8 @@ static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt, out: if (!rc) __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITHOST); + else + icmp_global_consume(); return rc; } @@ -402,6 +409,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) struct ipcm_cookie ipc; struct rtable *rt = skb_rtable(skb); struct net *net = dev_net(rt->dst.dev); + bool apply_ratelimit = false; struct flowi4 fl4; struct sock *sk; struct inet_sock *inet; @@ -413,11 +421,11 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) if (ip_options_echo(net, &icmp_param->replyopts.opt.opt, skb)) return; - /* Needed by both icmp_global_allow and icmp_xmit_lock */ + /* Needed by both icmpv4_global_allow and icmp_xmit_lock */ local_bh_disable(); - /* global icmp_msgs_per_sec */ - if (!icmpv4_global_allow(net, type, code)) + /* is global icmp_msgs_per_sec exhausted ? */ + if (!icmpv4_global_allow(net, type, code, &apply_ratelimit)) goto out_bh_enable; sk = icmp_xmit_lock(net); @@ -450,7 +458,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) rt = ip_route_output_key(net, &fl4); if (IS_ERR(rt)) goto out_unlock; - if (icmpv4_xrlim_allow(net, rt, &fl4, type, code)) + if (icmpv4_xrlim_allow(net, rt, &fl4, type, code, apply_ratelimit)) icmp_push_reply(sk, icmp_param, &fl4, &ipc, &rt); ip_rt_put(rt); out_unlock: @@ -596,6 +604,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, int room; struct icmp_bxm icmp_param; struct rtable *rt = skb_rtable(skb_in); + bool apply_ratelimit = false; struct ipcm_cookie ipc; struct flowi4 fl4; __be32 saddr; @@ -677,7 +686,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, } } - /* Needed by both icmp_global_allow and icmp_xmit_lock */ + /* Needed by both icmpv4_global_allow and icmp_xmit_lock */ local_bh_disable(); /* Check global sysctl_icmp_msgs_per_sec ratelimit, unless @@ -685,7 +694,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, * loopback, then peer ratelimit still work (in icmpv4_xrlim_allow) */ if (!(skb_in->dev && (skb_in->dev->flags&IFF_LOOPBACK)) && - !icmpv4_global_allow(net, type, code)) + !icmpv4_global_allow(net, type, code, &apply_ratelimit)) goto out_bh_enable; sk = icmp_xmit_lock(net); @@ -744,7 +753,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, goto out_unlock; /* peer icmp_ratelimit */ - if (!icmpv4_xrlim_allow(net, rt, &fl4, type, code)) + if (!icmpv4_xrlim_allow(net, rt, &fl4, type, code, apply_ratelimit)) goto ende; /* RFC says return as much as we can without exceeding 576 bytes. */ diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 7b31674644ef..46f70e4a8351 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -175,14 +175,16 @@ static bool icmpv6_mask_allow(struct net *net, int type) return false; } -static bool icmpv6_global_allow(struct net *net, int type) +static bool icmpv6_global_allow(struct net *net, int type, + bool *apply_ratelimit) { if (icmpv6_mask_allow(net, type)) return true; - if (icmp_global_allow()) + if (icmp_global_allow()) { + *apply_ratelimit = true; return true; - + } __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITGLOBAL); return false; } @@ -191,13 +193,13 @@ static bool icmpv6_global_allow(struct net *net, int type) * Check the ICMP output rate limit */ static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, - struct flowi6 *fl6) + struct flowi6 *fl6, bool apply_ratelimit) { struct net *net = sock_net(sk); struct dst_entry *dst; bool res = false; - if (icmpv6_mask_allow(net, type)) + if (!apply_ratelimit) return true; /* @@ -228,6 +230,8 @@ static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, if (!res) __ICMP6_INC_STATS(net, ip6_dst_idev(dst), ICMP6_MIB_RATELIMITHOST); + else + icmp_global_consume(); dst_release(dst); return res; } @@ -452,6 +456,7 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, struct net *net; struct ipv6_pinfo *np; const struct in6_addr *saddr = NULL; + bool apply_ratelimit = false; struct dst_entry *dst; struct icmp6hdr tmp_hdr; struct flowi6 fl6; @@ -533,11 +538,12 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, return; } - /* Needed by both icmp_global_allow and icmpv6_xmit_lock */ + /* Needed by both icmpv6_global_allow and icmpv6_xmit_lock */ local_bh_disable(); /* Check global sysctl_icmp_msgs_per_sec ratelimit */ - if (!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, type)) + if (!(skb->dev->flags & IFF_LOOPBACK) && + !icmpv6_global_allow(net, type, &apply_ratelimit)) goto out_bh_enable; mip6_addr_swap(skb, parm); @@ -575,7 +581,7 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, np = inet6_sk(sk); - if (!icmpv6_xrlim_allow(sk, type, &fl6)) + if (!icmpv6_xrlim_allow(sk, type, &fl6, apply_ratelimit)) goto out; tmp_hdr.icmp6_type = type; @@ -717,6 +723,7 @@ static enum skb_drop_reason icmpv6_echo_reply(struct sk_buff *skb) struct ipv6_pinfo *np; const struct in6_addr *saddr = NULL; struct icmp6hdr *icmph = icmp6_hdr(skb); + bool apply_ratelimit = false; struct icmp6hdr tmp_hdr; struct flowi6 fl6; struct icmpv6_msg msg; @@ -781,8 +788,9 @@ static enum skb_drop_reason icmpv6_echo_reply(struct sk_buff *skb) goto out; /* Check the ratelimit */ - if ((!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY)) || - !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6)) + if ((!(skb->dev->flags & IFF_LOOPBACK) && + !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY, &apply_ratelimit)) || + !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6, apply_ratelimit)) goto out_dst_release; idev = __in6_dev_get(skb->dev);

7 months, 1 week

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FAILED: patch "[PATCH] icmp: change the order of rate limits" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 8c2bd38b95f75f3d2a08c93e35303e26d480d24e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100130-replay-varied-aaaf@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: 8c2bd38b95f7 ("icmp: change the order of rate limits") d0941130c935 ("icmp: Add counters for rate limits") 8032bf1233a7 ("treewide: use get_random_u32_below() instead of deprecated function") c5f0a1728874 ("rhashtable: make test actually random") 197173db990c ("treewide: use get_random_bytes() when possible") a251c17aa558 ("treewide: use get_random_u32() when possible") 7e3cf0843fe5 ("treewide: use get_random_{u8,u16}() when possible, part 1") 8b3ccbc1f1f9 ("treewide: use prandom_u32_max() when possible, part 2") 81895a65ec63 ("treewide: use prandom_u32_max() when possible, part 1") 27bc50fc9064 ("Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 8c2bd38b95f75f3d2a08c93e35303e26d480d24e Mon Sep 17 00:00:00 2001 From: Eric Dumazet <edumazet(a)google.com> Date: Thu, 29 Aug 2024 14:46:39 +0000 Subject: [PATCH] icmp: change the order of rate limits ICMP messages are ratelimited : After the blamed commits, the two rate limiters are applied in this order: 1) host wide ratelimit (icmp_global_allow()) 2) Per destination ratelimit (inetpeer based) In order to avoid side-channels attacks, we need to apply the per destination check first. This patch makes the following change : 1) icmp_global_allow() checks if the host wide limit is reached. But credits are not yet consumed. This is deferred to 3) 2) The per destination limit is checked/updated. This might add a new node in inetpeer tree. 3) icmp_global_consume() consumes tokens if prior operations succeeded. This means that host wide ratelimit is still effective in keeping inetpeer tree small even under DDOS. As a bonus, I removed icmp_global.lock as the fast path can use a lock-free operation. Fixes: c0303efeab73 ("net: reduce cycles spend on ICMP replies that gets rate limited") Fixes: 4cdf507d5452 ("icmp: add a global rate limitation") Reported-by: Keyu Man <keyu.man(a)email.ucr.edu> Signed-off-by: Eric Dumazet <edumazet(a)google.com> Reviewed-by: David Ahern <dsahern(a)kernel.org> Cc: Jesper Dangaard Brouer <hawk(a)kernel.org> Cc: stable(a)vger.kernel.org Link: https://patch.msgid.link/20240829144641.3880376-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> diff --git a/include/net/ip.h b/include/net/ip.h index c5606cadb1a5..82248813619e 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -795,6 +795,8 @@ static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb) } bool icmp_global_allow(void); +void icmp_global_consume(void); + extern int sysctl_icmp_msgs_per_sec; extern int sysctl_icmp_msgs_burst; diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index b8f56d03fcbb..0078e8fb2e86 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -224,57 +224,59 @@ int sysctl_icmp_msgs_per_sec __read_mostly = 1000; int sysctl_icmp_msgs_burst __read_mostly = 50; static struct { - spinlock_t lock; - u32 credit; + atomic_t credit; u32 stamp; -} icmp_global = { - .lock = __SPIN_LOCK_UNLOCKED(icmp_global.lock), -}; +} icmp_global; /** * icmp_global_allow - Are we allowed to send one more ICMP message ? * * Uses a token bucket to limit our ICMP messages to ~sysctl_icmp_msgs_per_sec. * Returns false if we reached the limit and can not send another packet. - * Note: called with BH disabled + * Works in tandem with icmp_global_consume(). */ bool icmp_global_allow(void) { - u32 credit, delta, incr = 0, now = (u32)jiffies; - bool rc = false; + u32 delta, now, oldstamp; + int incr, new, old; - /* Check if token bucket is empty and cannot be refilled - * without taking the spinlock. The READ_ONCE() are paired - * with the following WRITE_ONCE() in this same function. + /* Note: many cpus could find this condition true. + * Then later icmp_global_consume() could consume more credits, + * this is an acceptable race. */ - if (!READ_ONCE(icmp_global.credit)) { - delta = min_t(u32, now - READ_ONCE(icmp_global.stamp), HZ); - if (delta < HZ / 50) - return false; - } + if (atomic_read(&icmp_global.credit) > 0) + return true; - spin_lock(&icmp_global.lock); - delta = min_t(u32, now - icmp_global.stamp, HZ); - if (delta >= HZ / 50) { - incr = READ_ONCE(sysctl_icmp_msgs_per_sec) * delta / HZ; - if (incr) - WRITE_ONCE(icmp_global.stamp, now); + now = jiffies; + oldstamp = READ_ONCE(icmp_global.stamp); + delta = min_t(u32, now - oldstamp, HZ); + if (delta < HZ / 50) + return false; + + incr = READ_ONCE(sysctl_icmp_msgs_per_sec) * delta / HZ; + if (!incr) + return false; + + if (cmpxchg(&icmp_global.stamp, oldstamp, now) == oldstamp) { + old = atomic_read(&icmp_global.credit); + do { + new = min(old + incr, READ_ONCE(sysctl_icmp_msgs_burst)); + } while (!atomic_try_cmpxchg(&icmp_global.credit, &old, new)); } - credit = min_t(u32, icmp_global.credit + incr, - READ_ONCE(sysctl_icmp_msgs_burst)); - if (credit) { - /* We want to use a credit of one in average, but need to randomize - * it for security reasons. - */ - credit = max_t(int, credit - get_random_u32_below(3), 0); - rc = true; - } - WRITE_ONCE(icmp_global.credit, credit); - spin_unlock(&icmp_global.lock); - return rc; + return true; } EXPORT_SYMBOL(icmp_global_allow); +void icmp_global_consume(void) +{ + int credits = get_random_u32_below(3); + + /* Note: this might make icmp_global.credit negative. */ + if (credits) + atomic_sub(credits, &icmp_global.credit); +} +EXPORT_SYMBOL(icmp_global_consume); + static bool icmpv4_mask_allow(struct net *net, int type, int code) { if (type > NR_ICMP_TYPES) @@ -291,14 +293,16 @@ static bool icmpv4_mask_allow(struct net *net, int type, int code) return false; } -static bool icmpv4_global_allow(struct net *net, int type, int code) +static bool icmpv4_global_allow(struct net *net, int type, int code, + bool *apply_ratelimit) { if (icmpv4_mask_allow(net, type, code)) return true; - if (icmp_global_allow()) + if (icmp_global_allow()) { + *apply_ratelimit = true; return true; - + } __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITGLOBAL); return false; } @@ -308,15 +312,16 @@ static bool icmpv4_global_allow(struct net *net, int type, int code) */ static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt, - struct flowi4 *fl4, int type, int code) + struct flowi4 *fl4, int type, int code, + bool apply_ratelimit) { struct dst_entry *dst = &rt->dst; struct inet_peer *peer; bool rc = true; int vif; - if (icmpv4_mask_allow(net, type, code)) - goto out; + if (!apply_ratelimit) + return true; /* No rate limit on loopback */ if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) @@ -331,6 +336,8 @@ static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt, out: if (!rc) __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITHOST); + else + icmp_global_consume(); return rc; } @@ -402,6 +409,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) struct ipcm_cookie ipc; struct rtable *rt = skb_rtable(skb); struct net *net = dev_net(rt->dst.dev); + bool apply_ratelimit = false; struct flowi4 fl4; struct sock *sk; struct inet_sock *inet; @@ -413,11 +421,11 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) if (ip_options_echo(net, &icmp_param->replyopts.opt.opt, skb)) return; - /* Needed by both icmp_global_allow and icmp_xmit_lock */ + /* Needed by both icmpv4_global_allow and icmp_xmit_lock */ local_bh_disable(); - /* global icmp_msgs_per_sec */ - if (!icmpv4_global_allow(net, type, code)) + /* is global icmp_msgs_per_sec exhausted ? */ + if (!icmpv4_global_allow(net, type, code, &apply_ratelimit)) goto out_bh_enable; sk = icmp_xmit_lock(net); @@ -450,7 +458,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) rt = ip_route_output_key(net, &fl4); if (IS_ERR(rt)) goto out_unlock; - if (icmpv4_xrlim_allow(net, rt, &fl4, type, code)) + if (icmpv4_xrlim_allow(net, rt, &fl4, type, code, apply_ratelimit)) icmp_push_reply(sk, icmp_param, &fl4, &ipc, &rt); ip_rt_put(rt); out_unlock: @@ -596,6 +604,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, int room; struct icmp_bxm icmp_param; struct rtable *rt = skb_rtable(skb_in); + bool apply_ratelimit = false; struct ipcm_cookie ipc; struct flowi4 fl4; __be32 saddr; @@ -677,7 +686,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, } } - /* Needed by both icmp_global_allow and icmp_xmit_lock */ + /* Needed by both icmpv4_global_allow and icmp_xmit_lock */ local_bh_disable(); /* Check global sysctl_icmp_msgs_per_sec ratelimit, unless @@ -685,7 +694,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, * loopback, then peer ratelimit still work (in icmpv4_xrlim_allow) */ if (!(skb_in->dev && (skb_in->dev->flags&IFF_LOOPBACK)) && - !icmpv4_global_allow(net, type, code)) + !icmpv4_global_allow(net, type, code, &apply_ratelimit)) goto out_bh_enable; sk = icmp_xmit_lock(net); @@ -744,7 +753,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, goto out_unlock; /* peer icmp_ratelimit */ - if (!icmpv4_xrlim_allow(net, rt, &fl4, type, code)) + if (!icmpv4_xrlim_allow(net, rt, &fl4, type, code, apply_ratelimit)) goto ende; /* RFC says return as much as we can without exceeding 576 bytes. */ diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 7b31674644ef..46f70e4a8351 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -175,14 +175,16 @@ static bool icmpv6_mask_allow(struct net *net, int type) return false; } -static bool icmpv6_global_allow(struct net *net, int type) +static bool icmpv6_global_allow(struct net *net, int type, + bool *apply_ratelimit) { if (icmpv6_mask_allow(net, type)) return true; - if (icmp_global_allow()) + if (icmp_global_allow()) { + *apply_ratelimit = true; return true; - + } __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITGLOBAL); return false; } @@ -191,13 +193,13 @@ static bool icmpv6_global_allow(struct net *net, int type) * Check the ICMP output rate limit */ static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, - struct flowi6 *fl6) + struct flowi6 *fl6, bool apply_ratelimit) { struct net *net = sock_net(sk); struct dst_entry *dst; bool res = false; - if (icmpv6_mask_allow(net, type)) + if (!apply_ratelimit) return true; /* @@ -228,6 +230,8 @@ static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, if (!res) __ICMP6_INC_STATS(net, ip6_dst_idev(dst), ICMP6_MIB_RATELIMITHOST); + else + icmp_global_consume(); dst_release(dst); return res; } @@ -452,6 +456,7 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, struct net *net; struct ipv6_pinfo *np; const struct in6_addr *saddr = NULL; + bool apply_ratelimit = false; struct dst_entry *dst; struct icmp6hdr tmp_hdr; struct flowi6 fl6; @@ -533,11 +538,12 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, return; } - /* Needed by both icmp_global_allow and icmpv6_xmit_lock */ + /* Needed by both icmpv6_global_allow and icmpv6_xmit_lock */ local_bh_disable(); /* Check global sysctl_icmp_msgs_per_sec ratelimit */ - if (!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, type)) + if (!(skb->dev->flags & IFF_LOOPBACK) && + !icmpv6_global_allow(net, type, &apply_ratelimit)) goto out_bh_enable; mip6_addr_swap(skb, parm); @@ -575,7 +581,7 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, np = inet6_sk(sk); - if (!icmpv6_xrlim_allow(sk, type, &fl6)) + if (!icmpv6_xrlim_allow(sk, type, &fl6, apply_ratelimit)) goto out; tmp_hdr.icmp6_type = type; @@ -717,6 +723,7 @@ static enum skb_drop_reason icmpv6_echo_reply(struct sk_buff *skb) struct ipv6_pinfo *np; const struct in6_addr *saddr = NULL; struct icmp6hdr *icmph = icmp6_hdr(skb); + bool apply_ratelimit = false; struct icmp6hdr tmp_hdr; struct flowi6 fl6; struct icmpv6_msg msg; @@ -781,8 +788,9 @@ static enum skb_drop_reason icmpv6_echo_reply(struct sk_buff *skb) goto out; /* Check the ratelimit */ - if ((!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY)) || - !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6)) + if ((!(skb->dev->flags & IFF_LOOPBACK) && + !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY, &apply_ratelimit)) || + !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6, apply_ratelimit)) goto out_dst_release; idev = __in6_dev_get(skb->dev);

7 months, 1 week

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FAILED: patch "[PATCH] icmp: change the order of rate limits" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 8c2bd38b95f75f3d2a08c93e35303e26d480d24e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100129-cottage-pushiness-6e12@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: 8c2bd38b95f7 ("icmp: change the order of rate limits") d0941130c935 ("icmp: Add counters for rate limits") 8032bf1233a7 ("treewide: use get_random_u32_below() instead of deprecated function") c5f0a1728874 ("rhashtable: make test actually random") 197173db990c ("treewide: use get_random_bytes() when possible") a251c17aa558 ("treewide: use get_random_u32() when possible") 7e3cf0843fe5 ("treewide: use get_random_{u8,u16}() when possible, part 1") 8b3ccbc1f1f9 ("treewide: use prandom_u32_max() when possible, part 2") 81895a65ec63 ("treewide: use prandom_u32_max() when possible, part 1") 27bc50fc9064 ("Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 8c2bd38b95f75f3d2a08c93e35303e26d480d24e Mon Sep 17 00:00:00 2001 From: Eric Dumazet <edumazet(a)google.com> Date: Thu, 29 Aug 2024 14:46:39 +0000 Subject: [PATCH] icmp: change the order of rate limits ICMP messages are ratelimited : After the blamed commits, the two rate limiters are applied in this order: 1) host wide ratelimit (icmp_global_allow()) 2) Per destination ratelimit (inetpeer based) In order to avoid side-channels attacks, we need to apply the per destination check first. This patch makes the following change : 1) icmp_global_allow() checks if the host wide limit is reached. But credits are not yet consumed. This is deferred to 3) 2) The per destination limit is checked/updated. This might add a new node in inetpeer tree. 3) icmp_global_consume() consumes tokens if prior operations succeeded. This means that host wide ratelimit is still effective in keeping inetpeer tree small even under DDOS. As a bonus, I removed icmp_global.lock as the fast path can use a lock-free operation. Fixes: c0303efeab73 ("net: reduce cycles spend on ICMP replies that gets rate limited") Fixes: 4cdf507d5452 ("icmp: add a global rate limitation") Reported-by: Keyu Man <keyu.man(a)email.ucr.edu> Signed-off-by: Eric Dumazet <edumazet(a)google.com> Reviewed-by: David Ahern <dsahern(a)kernel.org> Cc: Jesper Dangaard Brouer <hawk(a)kernel.org> Cc: stable(a)vger.kernel.org Link: https://patch.msgid.link/20240829144641.3880376-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> diff --git a/include/net/ip.h b/include/net/ip.h index c5606cadb1a5..82248813619e 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -795,6 +795,8 @@ static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb) } bool icmp_global_allow(void); +void icmp_global_consume(void); + extern int sysctl_icmp_msgs_per_sec; extern int sysctl_icmp_msgs_burst; diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index b8f56d03fcbb..0078e8fb2e86 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -224,57 +224,59 @@ int sysctl_icmp_msgs_per_sec __read_mostly = 1000; int sysctl_icmp_msgs_burst __read_mostly = 50; static struct { - spinlock_t lock; - u32 credit; + atomic_t credit; u32 stamp; -} icmp_global = { - .lock = __SPIN_LOCK_UNLOCKED(icmp_global.lock), -}; +} icmp_global; /** * icmp_global_allow - Are we allowed to send one more ICMP message ? * * Uses a token bucket to limit our ICMP messages to ~sysctl_icmp_msgs_per_sec. * Returns false if we reached the limit and can not send another packet. - * Note: called with BH disabled + * Works in tandem with icmp_global_consume(). */ bool icmp_global_allow(void) { - u32 credit, delta, incr = 0, now = (u32)jiffies; - bool rc = false; + u32 delta, now, oldstamp; + int incr, new, old; - /* Check if token bucket is empty and cannot be refilled - * without taking the spinlock. The READ_ONCE() are paired - * with the following WRITE_ONCE() in this same function. + /* Note: many cpus could find this condition true. + * Then later icmp_global_consume() could consume more credits, + * this is an acceptable race. */ - if (!READ_ONCE(icmp_global.credit)) { - delta = min_t(u32, now - READ_ONCE(icmp_global.stamp), HZ); - if (delta < HZ / 50) - return false; - } + if (atomic_read(&icmp_global.credit) > 0) + return true; - spin_lock(&icmp_global.lock); - delta = min_t(u32, now - icmp_global.stamp, HZ); - if (delta >= HZ / 50) { - incr = READ_ONCE(sysctl_icmp_msgs_per_sec) * delta / HZ; - if (incr) - WRITE_ONCE(icmp_global.stamp, now); + now = jiffies; + oldstamp = READ_ONCE(icmp_global.stamp); + delta = min_t(u32, now - oldstamp, HZ); + if (delta < HZ / 50) + return false; + + incr = READ_ONCE(sysctl_icmp_msgs_per_sec) * delta / HZ; + if (!incr) + return false; + + if (cmpxchg(&icmp_global.stamp, oldstamp, now) == oldstamp) { + old = atomic_read(&icmp_global.credit); + do { + new = min(old + incr, READ_ONCE(sysctl_icmp_msgs_burst)); + } while (!atomic_try_cmpxchg(&icmp_global.credit, &old, new)); } - credit = min_t(u32, icmp_global.credit + incr, - READ_ONCE(sysctl_icmp_msgs_burst)); - if (credit) { - /* We want to use a credit of one in average, but need to randomize - * it for security reasons. - */ - credit = max_t(int, credit - get_random_u32_below(3), 0); - rc = true; - } - WRITE_ONCE(icmp_global.credit, credit); - spin_unlock(&icmp_global.lock); - return rc; + return true; } EXPORT_SYMBOL(icmp_global_allow); +void icmp_global_consume(void) +{ + int credits = get_random_u32_below(3); + + /* Note: this might make icmp_global.credit negative. */ + if (credits) + atomic_sub(credits, &icmp_global.credit); +} +EXPORT_SYMBOL(icmp_global_consume); + static bool icmpv4_mask_allow(struct net *net, int type, int code) { if (type > NR_ICMP_TYPES) @@ -291,14 +293,16 @@ static bool icmpv4_mask_allow(struct net *net, int type, int code) return false; } -static bool icmpv4_global_allow(struct net *net, int type, int code) +static bool icmpv4_global_allow(struct net *net, int type, int code, + bool *apply_ratelimit) { if (icmpv4_mask_allow(net, type, code)) return true; - if (icmp_global_allow()) + if (icmp_global_allow()) { + *apply_ratelimit = true; return true; - + } __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITGLOBAL); return false; } @@ -308,15 +312,16 @@ static bool icmpv4_global_allow(struct net *net, int type, int code) */ static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt, - struct flowi4 *fl4, int type, int code) + struct flowi4 *fl4, int type, int code, + bool apply_ratelimit) { struct dst_entry *dst = &rt->dst; struct inet_peer *peer; bool rc = true; int vif; - if (icmpv4_mask_allow(net, type, code)) - goto out; + if (!apply_ratelimit) + return true; /* No rate limit on loopback */ if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) @@ -331,6 +336,8 @@ static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt, out: if (!rc) __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITHOST); + else + icmp_global_consume(); return rc; } @@ -402,6 +409,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) struct ipcm_cookie ipc; struct rtable *rt = skb_rtable(skb); struct net *net = dev_net(rt->dst.dev); + bool apply_ratelimit = false; struct flowi4 fl4; struct sock *sk; struct inet_sock *inet; @@ -413,11 +421,11 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) if (ip_options_echo(net, &icmp_param->replyopts.opt.opt, skb)) return; - /* Needed by both icmp_global_allow and icmp_xmit_lock */ + /* Needed by both icmpv4_global_allow and icmp_xmit_lock */ local_bh_disable(); - /* global icmp_msgs_per_sec */ - if (!icmpv4_global_allow(net, type, code)) + /* is global icmp_msgs_per_sec exhausted ? */ + if (!icmpv4_global_allow(net, type, code, &apply_ratelimit)) goto out_bh_enable; sk = icmp_xmit_lock(net); @@ -450,7 +458,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) rt = ip_route_output_key(net, &fl4); if (IS_ERR(rt)) goto out_unlock; - if (icmpv4_xrlim_allow(net, rt, &fl4, type, code)) + if (icmpv4_xrlim_allow(net, rt, &fl4, type, code, apply_ratelimit)) icmp_push_reply(sk, icmp_param, &fl4, &ipc, &rt); ip_rt_put(rt); out_unlock: @@ -596,6 +604,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, int room; struct icmp_bxm icmp_param; struct rtable *rt = skb_rtable(skb_in); + bool apply_ratelimit = false; struct ipcm_cookie ipc; struct flowi4 fl4; __be32 saddr; @@ -677,7 +686,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, } } - /* Needed by both icmp_global_allow and icmp_xmit_lock */ + /* Needed by both icmpv4_global_allow and icmp_xmit_lock */ local_bh_disable(); /* Check global sysctl_icmp_msgs_per_sec ratelimit, unless @@ -685,7 +694,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, * loopback, then peer ratelimit still work (in icmpv4_xrlim_allow) */ if (!(skb_in->dev && (skb_in->dev->flags&IFF_LOOPBACK)) && - !icmpv4_global_allow(net, type, code)) + !icmpv4_global_allow(net, type, code, &apply_ratelimit)) goto out_bh_enable; sk = icmp_xmit_lock(net); @@ -744,7 +753,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, goto out_unlock; /* peer icmp_ratelimit */ - if (!icmpv4_xrlim_allow(net, rt, &fl4, type, code)) + if (!icmpv4_xrlim_allow(net, rt, &fl4, type, code, apply_ratelimit)) goto ende; /* RFC says return as much as we can without exceeding 576 bytes. */ diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 7b31674644ef..46f70e4a8351 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -175,14 +175,16 @@ static bool icmpv6_mask_allow(struct net *net, int type) return false; } -static bool icmpv6_global_allow(struct net *net, int type) +static bool icmpv6_global_allow(struct net *net, int type, + bool *apply_ratelimit) { if (icmpv6_mask_allow(net, type)) return true; - if (icmp_global_allow()) + if (icmp_global_allow()) { + *apply_ratelimit = true; return true; - + } __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITGLOBAL); return false; } @@ -191,13 +193,13 @@ static bool icmpv6_global_allow(struct net *net, int type) * Check the ICMP output rate limit */ static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, - struct flowi6 *fl6) + struct flowi6 *fl6, bool apply_ratelimit) { struct net *net = sock_net(sk); struct dst_entry *dst; bool res = false; - if (icmpv6_mask_allow(net, type)) + if (!apply_ratelimit) return true; /* @@ -228,6 +230,8 @@ static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, if (!res) __ICMP6_INC_STATS(net, ip6_dst_idev(dst), ICMP6_MIB_RATELIMITHOST); + else + icmp_global_consume(); dst_release(dst); return res; } @@ -452,6 +456,7 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, struct net *net; struct ipv6_pinfo *np; const struct in6_addr *saddr = NULL; + bool apply_ratelimit = false; struct dst_entry *dst; struct icmp6hdr tmp_hdr; struct flowi6 fl6; @@ -533,11 +538,12 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, return; } - /* Needed by both icmp_global_allow and icmpv6_xmit_lock */ + /* Needed by both icmpv6_global_allow and icmpv6_xmit_lock */ local_bh_disable(); /* Check global sysctl_icmp_msgs_per_sec ratelimit */ - if (!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, type)) + if (!(skb->dev->flags & IFF_LOOPBACK) && + !icmpv6_global_allow(net, type, &apply_ratelimit)) goto out_bh_enable; mip6_addr_swap(skb, parm); @@ -575,7 +581,7 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, np = inet6_sk(sk); - if (!icmpv6_xrlim_allow(sk, type, &fl6)) + if (!icmpv6_xrlim_allow(sk, type, &fl6, apply_ratelimit)) goto out; tmp_hdr.icmp6_type = type; @@ -717,6 +723,7 @@ static enum skb_drop_reason icmpv6_echo_reply(struct sk_buff *skb) struct ipv6_pinfo *np; const struct in6_addr *saddr = NULL; struct icmp6hdr *icmph = icmp6_hdr(skb); + bool apply_ratelimit = false; struct icmp6hdr tmp_hdr; struct flowi6 fl6; struct icmpv6_msg msg; @@ -781,8 +788,9 @@ static enum skb_drop_reason icmpv6_echo_reply(struct sk_buff *skb) goto out; /* Check the ratelimit */ - if ((!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY)) || - !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6)) + if ((!(skb->dev->flags & IFF_LOOPBACK) && + !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY, &apply_ratelimit)) || + !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6, apply_ratelimit)) goto out_dst_release; idev = __in6_dev_get(skb->dev);

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FAILED: patch "[PATCH] icmp: change the order of rate limits" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 8c2bd38b95f75f3d2a08c93e35303e26d480d24e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100128-unsealed-flakily-f407@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: 8c2bd38b95f7 ("icmp: change the order of rate limits") d0941130c935 ("icmp: Add counters for rate limits") 8032bf1233a7 ("treewide: use get_random_u32_below() instead of deprecated function") c5f0a1728874 ("rhashtable: make test actually random") 197173db990c ("treewide: use get_random_bytes() when possible") a251c17aa558 ("treewide: use get_random_u32() when possible") 7e3cf0843fe5 ("treewide: use get_random_{u8,u16}() when possible, part 1") 8b3ccbc1f1f9 ("treewide: use prandom_u32_max() when possible, part 2") 81895a65ec63 ("treewide: use prandom_u32_max() when possible, part 1") 27bc50fc9064 ("Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 8c2bd38b95f75f3d2a08c93e35303e26d480d24e Mon Sep 17 00:00:00 2001 From: Eric Dumazet <edumazet(a)google.com> Date: Thu, 29 Aug 2024 14:46:39 +0000 Subject: [PATCH] icmp: change the order of rate limits ICMP messages are ratelimited : After the blamed commits, the two rate limiters are applied in this order: 1) host wide ratelimit (icmp_global_allow()) 2) Per destination ratelimit (inetpeer based) In order to avoid side-channels attacks, we need to apply the per destination check first. This patch makes the following change : 1) icmp_global_allow() checks if the host wide limit is reached. But credits are not yet consumed. This is deferred to 3) 2) The per destination limit is checked/updated. This might add a new node in inetpeer tree. 3) icmp_global_consume() consumes tokens if prior operations succeeded. This means that host wide ratelimit is still effective in keeping inetpeer tree small even under DDOS. As a bonus, I removed icmp_global.lock as the fast path can use a lock-free operation. Fixes: c0303efeab73 ("net: reduce cycles spend on ICMP replies that gets rate limited") Fixes: 4cdf507d5452 ("icmp: add a global rate limitation") Reported-by: Keyu Man <keyu.man(a)email.ucr.edu> Signed-off-by: Eric Dumazet <edumazet(a)google.com> Reviewed-by: David Ahern <dsahern(a)kernel.org> Cc: Jesper Dangaard Brouer <hawk(a)kernel.org> Cc: stable(a)vger.kernel.org Link: https://patch.msgid.link/20240829144641.3880376-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> diff --git a/include/net/ip.h b/include/net/ip.h index c5606cadb1a5..82248813619e 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -795,6 +795,8 @@ static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb) } bool icmp_global_allow(void); +void icmp_global_consume(void); + extern int sysctl_icmp_msgs_per_sec; extern int sysctl_icmp_msgs_burst; diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index b8f56d03fcbb..0078e8fb2e86 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -224,57 +224,59 @@ int sysctl_icmp_msgs_per_sec __read_mostly = 1000; int sysctl_icmp_msgs_burst __read_mostly = 50; static struct { - spinlock_t lock; - u32 credit; + atomic_t credit; u32 stamp; -} icmp_global = { - .lock = __SPIN_LOCK_UNLOCKED(icmp_global.lock), -}; +} icmp_global; /** * icmp_global_allow - Are we allowed to send one more ICMP message ? * * Uses a token bucket to limit our ICMP messages to ~sysctl_icmp_msgs_per_sec. * Returns false if we reached the limit and can not send another packet. - * Note: called with BH disabled + * Works in tandem with icmp_global_consume(). */ bool icmp_global_allow(void) { - u32 credit, delta, incr = 0, now = (u32)jiffies; - bool rc = false; + u32 delta, now, oldstamp; + int incr, new, old; - /* Check if token bucket is empty and cannot be refilled - * without taking the spinlock. The READ_ONCE() are paired - * with the following WRITE_ONCE() in this same function. + /* Note: many cpus could find this condition true. + * Then later icmp_global_consume() could consume more credits, + * this is an acceptable race. */ - if (!READ_ONCE(icmp_global.credit)) { - delta = min_t(u32, now - READ_ONCE(icmp_global.stamp), HZ); - if (delta < HZ / 50) - return false; - } + if (atomic_read(&icmp_global.credit) > 0) + return true; - spin_lock(&icmp_global.lock); - delta = min_t(u32, now - icmp_global.stamp, HZ); - if (delta >= HZ / 50) { - incr = READ_ONCE(sysctl_icmp_msgs_per_sec) * delta / HZ; - if (incr) - WRITE_ONCE(icmp_global.stamp, now); + now = jiffies; + oldstamp = READ_ONCE(icmp_global.stamp); + delta = min_t(u32, now - oldstamp, HZ); + if (delta < HZ / 50) + return false; + + incr = READ_ONCE(sysctl_icmp_msgs_per_sec) * delta / HZ; + if (!incr) + return false; + + if (cmpxchg(&icmp_global.stamp, oldstamp, now) == oldstamp) { + old = atomic_read(&icmp_global.credit); + do { + new = min(old + incr, READ_ONCE(sysctl_icmp_msgs_burst)); + } while (!atomic_try_cmpxchg(&icmp_global.credit, &old, new)); } - credit = min_t(u32, icmp_global.credit + incr, - READ_ONCE(sysctl_icmp_msgs_burst)); - if (credit) { - /* We want to use a credit of one in average, but need to randomize - * it for security reasons. - */ - credit = max_t(int, credit - get_random_u32_below(3), 0); - rc = true; - } - WRITE_ONCE(icmp_global.credit, credit); - spin_unlock(&icmp_global.lock); - return rc; + return true; } EXPORT_SYMBOL(icmp_global_allow); +void icmp_global_consume(void) +{ + int credits = get_random_u32_below(3); + + /* Note: this might make icmp_global.credit negative. */ + if (credits) + atomic_sub(credits, &icmp_global.credit); +} +EXPORT_SYMBOL(icmp_global_consume); + static bool icmpv4_mask_allow(struct net *net, int type, int code) { if (type > NR_ICMP_TYPES) @@ -291,14 +293,16 @@ static bool icmpv4_mask_allow(struct net *net, int type, int code) return false; } -static bool icmpv4_global_allow(struct net *net, int type, int code) +static bool icmpv4_global_allow(struct net *net, int type, int code, + bool *apply_ratelimit) { if (icmpv4_mask_allow(net, type, code)) return true; - if (icmp_global_allow()) + if (icmp_global_allow()) { + *apply_ratelimit = true; return true; - + } __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITGLOBAL); return false; } @@ -308,15 +312,16 @@ static bool icmpv4_global_allow(struct net *net, int type, int code) */ static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt, - struct flowi4 *fl4, int type, int code) + struct flowi4 *fl4, int type, int code, + bool apply_ratelimit) { struct dst_entry *dst = &rt->dst; struct inet_peer *peer; bool rc = true; int vif; - if (icmpv4_mask_allow(net, type, code)) - goto out; + if (!apply_ratelimit) + return true; /* No rate limit on loopback */ if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) @@ -331,6 +336,8 @@ static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt, out: if (!rc) __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITHOST); + else + icmp_global_consume(); return rc; } @@ -402,6 +409,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) struct ipcm_cookie ipc; struct rtable *rt = skb_rtable(skb); struct net *net = dev_net(rt->dst.dev); + bool apply_ratelimit = false; struct flowi4 fl4; struct sock *sk; struct inet_sock *inet; @@ -413,11 +421,11 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) if (ip_options_echo(net, &icmp_param->replyopts.opt.opt, skb)) return; - /* Needed by both icmp_global_allow and icmp_xmit_lock */ + /* Needed by both icmpv4_global_allow and icmp_xmit_lock */ local_bh_disable(); - /* global icmp_msgs_per_sec */ - if (!icmpv4_global_allow(net, type, code)) + /* is global icmp_msgs_per_sec exhausted ? */ + if (!icmpv4_global_allow(net, type, code, &apply_ratelimit)) goto out_bh_enable; sk = icmp_xmit_lock(net); @@ -450,7 +458,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) rt = ip_route_output_key(net, &fl4); if (IS_ERR(rt)) goto out_unlock; - if (icmpv4_xrlim_allow(net, rt, &fl4, type, code)) + if (icmpv4_xrlim_allow(net, rt, &fl4, type, code, apply_ratelimit)) icmp_push_reply(sk, icmp_param, &fl4, &ipc, &rt); ip_rt_put(rt); out_unlock: @@ -596,6 +604,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, int room; struct icmp_bxm icmp_param; struct rtable *rt = skb_rtable(skb_in); + bool apply_ratelimit = false; struct ipcm_cookie ipc; struct flowi4 fl4; __be32 saddr; @@ -677,7 +686,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, } } - /* Needed by both icmp_global_allow and icmp_xmit_lock */ + /* Needed by both icmpv4_global_allow and icmp_xmit_lock */ local_bh_disable(); /* Check global sysctl_icmp_msgs_per_sec ratelimit, unless @@ -685,7 +694,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, * loopback, then peer ratelimit still work (in icmpv4_xrlim_allow) */ if (!(skb_in->dev && (skb_in->dev->flags&IFF_LOOPBACK)) && - !icmpv4_global_allow(net, type, code)) + !icmpv4_global_allow(net, type, code, &apply_ratelimit)) goto out_bh_enable; sk = icmp_xmit_lock(net); @@ -744,7 +753,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, goto out_unlock; /* peer icmp_ratelimit */ - if (!icmpv4_xrlim_allow(net, rt, &fl4, type, code)) + if (!icmpv4_xrlim_allow(net, rt, &fl4, type, code, apply_ratelimit)) goto ende; /* RFC says return as much as we can without exceeding 576 bytes. */ diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 7b31674644ef..46f70e4a8351 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -175,14 +175,16 @@ static bool icmpv6_mask_allow(struct net *net, int type) return false; } -static bool icmpv6_global_allow(struct net *net, int type) +static bool icmpv6_global_allow(struct net *net, int type, + bool *apply_ratelimit) { if (icmpv6_mask_allow(net, type)) return true; - if (icmp_global_allow()) + if (icmp_global_allow()) { + *apply_ratelimit = true; return true; - + } __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITGLOBAL); return false; } @@ -191,13 +193,13 @@ static bool icmpv6_global_allow(struct net *net, int type) * Check the ICMP output rate limit */ static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, - struct flowi6 *fl6) + struct flowi6 *fl6, bool apply_ratelimit) { struct net *net = sock_net(sk); struct dst_entry *dst; bool res = false; - if (icmpv6_mask_allow(net, type)) + if (!apply_ratelimit) return true; /* @@ -228,6 +230,8 @@ static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, if (!res) __ICMP6_INC_STATS(net, ip6_dst_idev(dst), ICMP6_MIB_RATELIMITHOST); + else + icmp_global_consume(); dst_release(dst); return res; } @@ -452,6 +456,7 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, struct net *net; struct ipv6_pinfo *np; const struct in6_addr *saddr = NULL; + bool apply_ratelimit = false; struct dst_entry *dst; struct icmp6hdr tmp_hdr; struct flowi6 fl6; @@ -533,11 +538,12 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, return; } - /* Needed by both icmp_global_allow and icmpv6_xmit_lock */ + /* Needed by both icmpv6_global_allow and icmpv6_xmit_lock */ local_bh_disable(); /* Check global sysctl_icmp_msgs_per_sec ratelimit */ - if (!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, type)) + if (!(skb->dev->flags & IFF_LOOPBACK) && + !icmpv6_global_allow(net, type, &apply_ratelimit)) goto out_bh_enable; mip6_addr_swap(skb, parm); @@ -575,7 +581,7 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, np = inet6_sk(sk); - if (!icmpv6_xrlim_allow(sk, type, &fl6)) + if (!icmpv6_xrlim_allow(sk, type, &fl6, apply_ratelimit)) goto out; tmp_hdr.icmp6_type = type; @@ -717,6 +723,7 @@ static enum skb_drop_reason icmpv6_echo_reply(struct sk_buff *skb) struct ipv6_pinfo *np; const struct in6_addr *saddr = NULL; struct icmp6hdr *icmph = icmp6_hdr(skb); + bool apply_ratelimit = false; struct icmp6hdr tmp_hdr; struct flowi6 fl6; struct icmpv6_msg msg; @@ -781,8 +788,9 @@ static enum skb_drop_reason icmpv6_echo_reply(struct sk_buff *skb) goto out; /* Check the ratelimit */ - if ((!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY)) || - !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6)) + if ((!(skb->dev->flags & IFF_LOOPBACK) && + !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY, &apply_ratelimit)) || + !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6, apply_ratelimit)) goto out_dst_release; idev = __in6_dev_get(skb->dev);

7 months, 1 week

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FAILED: patch "[PATCH] f2fs: Require FMODE_WRITE for atomic write ioctls" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y git checkout FETCH_HEAD git cherry-pick -x 4f5a100f87f32cb65d4bb1ad282a08c92f6f591e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100136-reanalyze-footwork-21f0@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^.. Possible dependencies: 4f5a100f87f3 ("f2fs: Require FMODE_WRITE for atomic write ioctls") 01beba7957a2 ("fs: port inode_owner_or_capable() to mnt_idmap") f2d40141d5d9 ("fs: port inode_init_owner() to mnt_idmap") 4609e1f18e19 ("fs: port ->permission() to pass mnt_idmap") 8782a9aea3ab ("fs: port ->fileattr_set() to pass mnt_idmap") 13e83a4923be ("fs: port ->set_acl() to pass mnt_idmap") 77435322777d ("fs: port ->get_acl() to pass mnt_idmap") 011e2b717b1b ("fs: port ->tmpfile() to pass mnt_idmap") 5ebb29bee8d5 ("fs: port ->mknod() to pass mnt_idmap") c54bd91e9eab ("fs: port ->mkdir() to pass mnt_idmap") 7a77db95511c ("fs: port ->symlink() to pass mnt_idmap") 6c960e68aaed ("fs: port ->create() to pass mnt_idmap") b74d24f7a74f ("fs: port ->getattr() to pass mnt_idmap") c1632a0f1120 ("fs: port ->setattr() to pass mnt_idmap") abf08576afe3 ("fs: port vfs_*() helpers to struct mnt_idmap") 6022ec6ee2c3 ("Merge tag 'ntfs3_for_6.2' of https://github.com/Paragon-Software-Group/linux-ntfs3") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 4f5a100f87f32cb65d4bb1ad282a08c92f6f591e Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Tue, 6 Aug 2024 16:07:16 +0200 Subject: [PATCH] f2fs: Require FMODE_WRITE for atomic write ioctls The F2FS ioctls for starting and committing atomic writes check for inode_owner_or_capable(), but this does not give LSMs like SELinux or Landlock an opportunity to deny the write access - if the caller's FSUID matches the inode's UID, inode_owner_or_capable() immediately returns true. There are scenarios where LSMs want to deny a process the ability to write particular files, even files that the FSUID of the process owns; but this can currently partially be bypassed using atomic write ioctls in two ways: - F2FS_IOC_START_ATOMIC_REPLACE + F2FS_IOC_COMMIT_ATOMIC_WRITE can truncate an inode to size 0 - F2FS_IOC_START_ATOMIC_WRITE + F2FS_IOC_ABORT_ATOMIC_WRITE can revert changes another process concurrently made to a file Fix it by requiring FMODE_WRITE for these operations, just like for F2FS_IOC_MOVE_RANGE. Since any legitimate caller should only be using these ioctls when intending to write into the file, that seems unlikely to break anything. Fixes: 88b88a667971 ("f2fs: support atomic writes") Cc: stable(a)vger.kernel.org Signed-off-by: Jann Horn <jannh(a)google.com> Reviewed-by: Chao Yu <chao(a)kernel.org> Reviewed-by: Eric Biggers <ebiggers(a)google.com> Signed-off-by: Jaegeuk Kim <jaegeuk(a)kernel.org> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index bddcb2cd945a..2c591fbc75a9 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -2131,6 +2131,9 @@ static int f2fs_ioc_start_atomic_write(struct file *filp, bool truncate) loff_t isize; int ret; + if (!(filp->f_mode & FMODE_WRITE)) + return -EBADF; + if (!inode_owner_or_capable(idmap, inode)) return -EACCES; @@ -2239,6 +2242,9 @@ static int f2fs_ioc_commit_atomic_write(struct file *filp) struct mnt_idmap *idmap = file_mnt_idmap(filp); int ret; + if (!(filp->f_mode & FMODE_WRITE)) + return -EBADF; + if (!inode_owner_or_capable(idmap, inode)) return -EACCES; @@ -2271,6 +2277,9 @@ static int f2fs_ioc_abort_atomic_write(struct file *filp) struct mnt_idmap *idmap = file_mnt_idmap(filp); int ret; + if (!(filp->f_mode & FMODE_WRITE)) + return -EBADF; + if (!inode_owner_or_capable(idmap, inode)) return -EACCES;

7 months, 1 week

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FAILED: patch "[PATCH] f2fs: Require FMODE_WRITE for atomic write ioctls" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 4f5a100f87f32cb65d4bb1ad282a08c92f6f591e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100135-magenta-resigned-365f@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: 4f5a100f87f3 ("f2fs: Require FMODE_WRITE for atomic write ioctls") 01beba7957a2 ("fs: port inode_owner_or_capable() to mnt_idmap") f2d40141d5d9 ("fs: port inode_init_owner() to mnt_idmap") 4609e1f18e19 ("fs: port ->permission() to pass mnt_idmap") 8782a9aea3ab ("fs: port ->fileattr_set() to pass mnt_idmap") 13e83a4923be ("fs: port ->set_acl() to pass mnt_idmap") 77435322777d ("fs: port ->get_acl() to pass mnt_idmap") 011e2b717b1b ("fs: port ->tmpfile() to pass mnt_idmap") 5ebb29bee8d5 ("fs: port ->mknod() to pass mnt_idmap") c54bd91e9eab ("fs: port ->mkdir() to pass mnt_idmap") 7a77db95511c ("fs: port ->symlink() to pass mnt_idmap") 6c960e68aaed ("fs: port ->create() to pass mnt_idmap") b74d24f7a74f ("fs: port ->getattr() to pass mnt_idmap") c1632a0f1120 ("fs: port ->setattr() to pass mnt_idmap") abf08576afe3 ("fs: port vfs_*() helpers to struct mnt_idmap") 6022ec6ee2c3 ("Merge tag 'ntfs3_for_6.2' of https://github.com/Paragon-Software-Group/linux-ntfs3") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 4f5a100f87f32cb65d4bb1ad282a08c92f6f591e Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Tue, 6 Aug 2024 16:07:16 +0200 Subject: [PATCH] f2fs: Require FMODE_WRITE for atomic write ioctls The F2FS ioctls for starting and committing atomic writes check for inode_owner_or_capable(), but this does not give LSMs like SELinux or Landlock an opportunity to deny the write access - if the caller's FSUID matches the inode's UID, inode_owner_or_capable() immediately returns true. There are scenarios where LSMs want to deny a process the ability to write particular files, even files that the FSUID of the process owns; but this can currently partially be bypassed using atomic write ioctls in two ways: - F2FS_IOC_START_ATOMIC_REPLACE + F2FS_IOC_COMMIT_ATOMIC_WRITE can truncate an inode to size 0 - F2FS_IOC_START_ATOMIC_WRITE + F2FS_IOC_ABORT_ATOMIC_WRITE can revert changes another process concurrently made to a file Fix it by requiring FMODE_WRITE for these operations, just like for F2FS_IOC_MOVE_RANGE. Since any legitimate caller should only be using these ioctls when intending to write into the file, that seems unlikely to break anything. Fixes: 88b88a667971 ("f2fs: support atomic writes") Cc: stable(a)vger.kernel.org Signed-off-by: Jann Horn <jannh(a)google.com> Reviewed-by: Chao Yu <chao(a)kernel.org> Reviewed-by: Eric Biggers <ebiggers(a)google.com> Signed-off-by: Jaegeuk Kim <jaegeuk(a)kernel.org> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index bddcb2cd945a..2c591fbc75a9 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -2131,6 +2131,9 @@ static int f2fs_ioc_start_atomic_write(struct file *filp, bool truncate) loff_t isize; int ret; + if (!(filp->f_mode & FMODE_WRITE)) + return -EBADF; + if (!inode_owner_or_capable(idmap, inode)) return -EACCES; @@ -2239,6 +2242,9 @@ static int f2fs_ioc_commit_atomic_write(struct file *filp) struct mnt_idmap *idmap = file_mnt_idmap(filp); int ret; + if (!(filp->f_mode & FMODE_WRITE)) + return -EBADF; + if (!inode_owner_or_capable(idmap, inode)) return -EACCES; @@ -2271,6 +2277,9 @@ static int f2fs_ioc_abort_atomic_write(struct file *filp) struct mnt_idmap *idmap = file_mnt_idmap(filp); int ret; + if (!(filp->f_mode & FMODE_WRITE)) + return -EBADF; + if (!inode_owner_or_capable(idmap, inode)) return -EACCES;

7 months, 1 week

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FAILED: patch "[PATCH] f2fs: Require FMODE_WRITE for atomic write ioctls" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 4f5a100f87f32cb65d4bb1ad282a08c92f6f591e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100134-blustery-wisplike-6b11@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: 4f5a100f87f3 ("f2fs: Require FMODE_WRITE for atomic write ioctls") 01beba7957a2 ("fs: port inode_owner_or_capable() to mnt_idmap") f2d40141d5d9 ("fs: port inode_init_owner() to mnt_idmap") 4609e1f18e19 ("fs: port ->permission() to pass mnt_idmap") 8782a9aea3ab ("fs: port ->fileattr_set() to pass mnt_idmap") 13e83a4923be ("fs: port ->set_acl() to pass mnt_idmap") 77435322777d ("fs: port ->get_acl() to pass mnt_idmap") 011e2b717b1b ("fs: port ->tmpfile() to pass mnt_idmap") 5ebb29bee8d5 ("fs: port ->mknod() to pass mnt_idmap") c54bd91e9eab ("fs: port ->mkdir() to pass mnt_idmap") 7a77db95511c ("fs: port ->symlink() to pass mnt_idmap") 6c960e68aaed ("fs: port ->create() to pass mnt_idmap") b74d24f7a74f ("fs: port ->getattr() to pass mnt_idmap") c1632a0f1120 ("fs: port ->setattr() to pass mnt_idmap") abf08576afe3 ("fs: port vfs_*() helpers to struct mnt_idmap") 6022ec6ee2c3 ("Merge tag 'ntfs3_for_6.2' of https://github.com/Paragon-Software-Group/linux-ntfs3") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 4f5a100f87f32cb65d4bb1ad282a08c92f6f591e Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Tue, 6 Aug 2024 16:07:16 +0200 Subject: [PATCH] f2fs: Require FMODE_WRITE for atomic write ioctls The F2FS ioctls for starting and committing atomic writes check for inode_owner_or_capable(), but this does not give LSMs like SELinux or Landlock an opportunity to deny the write access - if the caller's FSUID matches the inode's UID, inode_owner_or_capable() immediately returns true. There are scenarios where LSMs want to deny a process the ability to write particular files, even files that the FSUID of the process owns; but this can currently partially be bypassed using atomic write ioctls in two ways: - F2FS_IOC_START_ATOMIC_REPLACE + F2FS_IOC_COMMIT_ATOMIC_WRITE can truncate an inode to size 0 - F2FS_IOC_START_ATOMIC_WRITE + F2FS_IOC_ABORT_ATOMIC_WRITE can revert changes another process concurrently made to a file Fix it by requiring FMODE_WRITE for these operations, just like for F2FS_IOC_MOVE_RANGE. Since any legitimate caller should only be using these ioctls when intending to write into the file, that seems unlikely to break anything. Fixes: 88b88a667971 ("f2fs: support atomic writes") Cc: stable(a)vger.kernel.org Signed-off-by: Jann Horn <jannh(a)google.com> Reviewed-by: Chao Yu <chao(a)kernel.org> Reviewed-by: Eric Biggers <ebiggers(a)google.com> Signed-off-by: Jaegeuk Kim <jaegeuk(a)kernel.org> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index bddcb2cd945a..2c591fbc75a9 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -2131,6 +2131,9 @@ static int f2fs_ioc_start_atomic_write(struct file *filp, bool truncate) loff_t isize; int ret; + if (!(filp->f_mode & FMODE_WRITE)) + return -EBADF; + if (!inode_owner_or_capable(idmap, inode)) return -EACCES; @@ -2239,6 +2242,9 @@ static int f2fs_ioc_commit_atomic_write(struct file *filp) struct mnt_idmap *idmap = file_mnt_idmap(filp); int ret; + if (!(filp->f_mode & FMODE_WRITE)) + return -EBADF; + if (!inode_owner_or_capable(idmap, inode)) return -EACCES; @@ -2271,6 +2277,9 @@ static int f2fs_ioc_abort_atomic_write(struct file *filp) struct mnt_idmap *idmap = file_mnt_idmap(filp); int ret; + if (!(filp->f_mode & FMODE_WRITE)) + return -EBADF; + if (!inode_owner_or_capable(idmap, inode)) return -EACCES;

7 months, 1 week

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FAILED: patch "[PATCH] f2fs: Require FMODE_WRITE for atomic write ioctls" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 4f5a100f87f32cb65d4bb1ad282a08c92f6f591e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100133-islamic-matriarch-4cee@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: 4f5a100f87f3 ("f2fs: Require FMODE_WRITE for atomic write ioctls") 01beba7957a2 ("fs: port inode_owner_or_capable() to mnt_idmap") f2d40141d5d9 ("fs: port inode_init_owner() to mnt_idmap") 4609e1f18e19 ("fs: port ->permission() to pass mnt_idmap") 8782a9aea3ab ("fs: port ->fileattr_set() to pass mnt_idmap") 13e83a4923be ("fs: port ->set_acl() to pass mnt_idmap") 77435322777d ("fs: port ->get_acl() to pass mnt_idmap") 011e2b717b1b ("fs: port ->tmpfile() to pass mnt_idmap") 5ebb29bee8d5 ("fs: port ->mknod() to pass mnt_idmap") c54bd91e9eab ("fs: port ->mkdir() to pass mnt_idmap") 7a77db95511c ("fs: port ->symlink() to pass mnt_idmap") 6c960e68aaed ("fs: port ->create() to pass mnt_idmap") b74d24f7a74f ("fs: port ->getattr() to pass mnt_idmap") c1632a0f1120 ("fs: port ->setattr() to pass mnt_idmap") abf08576afe3 ("fs: port vfs_*() helpers to struct mnt_idmap") 6022ec6ee2c3 ("Merge tag 'ntfs3_for_6.2' of https://github.com/Paragon-Software-Group/linux-ntfs3") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 4f5a100f87f32cb65d4bb1ad282a08c92f6f591e Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Tue, 6 Aug 2024 16:07:16 +0200 Subject: [PATCH] f2fs: Require FMODE_WRITE for atomic write ioctls The F2FS ioctls for starting and committing atomic writes check for inode_owner_or_capable(), but this does not give LSMs like SELinux or Landlock an opportunity to deny the write access - if the caller's FSUID matches the inode's UID, inode_owner_or_capable() immediately returns true. There are scenarios where LSMs want to deny a process the ability to write particular files, even files that the FSUID of the process owns; but this can currently partially be bypassed using atomic write ioctls in two ways: - F2FS_IOC_START_ATOMIC_REPLACE + F2FS_IOC_COMMIT_ATOMIC_WRITE can truncate an inode to size 0 - F2FS_IOC_START_ATOMIC_WRITE + F2FS_IOC_ABORT_ATOMIC_WRITE can revert changes another process concurrently made to a file Fix it by requiring FMODE_WRITE for these operations, just like for F2FS_IOC_MOVE_RANGE. Since any legitimate caller should only be using these ioctls when intending to write into the file, that seems unlikely to break anything. Fixes: 88b88a667971 ("f2fs: support atomic writes") Cc: stable(a)vger.kernel.org Signed-off-by: Jann Horn <jannh(a)google.com> Reviewed-by: Chao Yu <chao(a)kernel.org> Reviewed-by: Eric Biggers <ebiggers(a)google.com> Signed-off-by: Jaegeuk Kim <jaegeuk(a)kernel.org> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index bddcb2cd945a..2c591fbc75a9 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -2131,6 +2131,9 @@ static int f2fs_ioc_start_atomic_write(struct file *filp, bool truncate) loff_t isize; int ret; + if (!(filp->f_mode & FMODE_WRITE)) + return -EBADF; + if (!inode_owner_or_capable(idmap, inode)) return -EACCES; @@ -2239,6 +2242,9 @@ static int f2fs_ioc_commit_atomic_write(struct file *filp) struct mnt_idmap *idmap = file_mnt_idmap(filp); int ret; + if (!(filp->f_mode & FMODE_WRITE)) + return -EBADF; + if (!inode_owner_or_capable(idmap, inode)) return -EACCES; @@ -2271,6 +2277,9 @@ static int f2fs_ioc_abort_atomic_write(struct file *filp) struct mnt_idmap *idmap = file_mnt_idmap(filp); int ret; + if (!(filp->f_mode & FMODE_WRITE)) + return -EBADF; + if (!inode_owner_or_capable(idmap, inode)) return -EACCES;

7 months, 1 week

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