FAILED: patch "[PATCH] mptcp: pm: Fix uaf in __timer_delete_sync" failed to apply to 5.10-stable tree
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@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 b4cd80b0338945a94972ac3ed54f8338d2da2076 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024091330-reps-craftsman-ab67@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
b4cd80b03389 ("mptcp: pm: Fix uaf in __timer_delete_sync") d58300c3185b ("mptcp: validate 'id' when stopping the ADD_ADDR retransmit timer") f7dafee18538 ("mptcp: use mptcp_addr_info in mptcp_options_received") dc87efdb1a5c ("mptcp: add mptcp reset option support") 557963c383e8 ("mptcp: move to next addr when subflow creation fail") d88c476f4a7d ("mptcp: export lookup_anno_list_by_saddr") efd13b71a3fa ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b4cd80b0338945a94972ac3ed54f8338d2da2076 Mon Sep 17 00:00:00 2001 From: Edward Adam Davis eadavis@qq.com Date: Tue, 10 Sep 2024 17:58:56 +0800 Subject: [PATCH] mptcp: pm: Fix uaf in __timer_delete_sync
There are two paths to access mptcp_pm_del_add_timer, result in a race condition:
CPU1 CPU2 ==== ==== net_rx_action napi_poll netlink_sendmsg __napi_poll netlink_unicast process_backlog netlink_unicast_kernel __netif_receive_skb genl_rcv __netif_receive_skb_one_core netlink_rcv_skb NF_HOOK genl_rcv_msg ip_local_deliver_finish genl_family_rcv_msg ip_protocol_deliver_rcu genl_family_rcv_msg_doit tcp_v4_rcv mptcp_pm_nl_flush_addrs_doit tcp_v4_do_rcv mptcp_nl_remove_addrs_list tcp_rcv_established mptcp_pm_remove_addrs_and_subflows tcp_data_queue remove_anno_list_by_saddr mptcp_incoming_options mptcp_pm_del_add_timer mptcp_pm_del_add_timer kfree(entry)
In remove_anno_list_by_saddr(running on CPU2), after leaving the critical zone protected by "pm.lock", the entry will be released, which leads to the occurrence of uaf in the mptcp_pm_del_add_timer(running on CPU1).
Keeping a reference to add_timer inside the lock, and calling sk_stop_timer_sync() with this reference, instead of "entry->add_timer".
Move list_del(&entry->list) to mptcp_pm_del_add_timer and inside the pm lock, do not directly access any members of the entry outside the pm lock, which can avoid similar "entry->x" uaf.
Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout") Cc: stable@vger.kernel.org Reported-and-tested-by: syzbot+f3a31fb909db9b2a5c4d@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f3a31fb909db9b2a5c4d Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org Signed-off-by: Edward Adam Davis eadavis@qq.com Acked-by: Paolo Abeni pabeni@redhat.com Link: https://patch.msgid.link/tencent_7142963A37944B4A74EF76CD66EA3C253609@qq.com Signed-off-by: Jakub Kicinski kuba@kernel.org
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index f891bc714668..ad935d34c973 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -334,15 +334,21 @@ mptcp_pm_del_add_timer(struct mptcp_sock *msk, { struct mptcp_pm_add_entry *entry; struct sock *sk = (struct sock *)msk; + struct timer_list *add_timer = NULL;
spin_lock_bh(&msk->pm.lock); entry = mptcp_lookup_anno_list_by_saddr(msk, addr); - if (entry && (!check_id || entry->addr.id == addr->id)) + if (entry && (!check_id || entry->addr.id == addr->id)) { entry->retrans_times = ADD_ADDR_RETRANS_MAX; + add_timer = &entry->add_timer; + } + if (!check_id && entry) + list_del(&entry->list); spin_unlock_bh(&msk->pm.lock);
- if (entry && (!check_id || entry->addr.id == addr->id)) - sk_stop_timer_sync(sk, &entry->add_timer); + /* no lock, because sk_stop_timer_sync() is calling del_timer_sync() */ + if (add_timer) + sk_stop_timer_sync(sk, add_timer);
return entry; } @@ -1462,7 +1468,6 @@ static bool remove_anno_list_by_saddr(struct mptcp_sock *msk,
entry = mptcp_pm_del_add_timer(msk, addr, false); if (entry) { - list_del(&entry->list); kfree(entry); return true; }
To ease the inclusion of commit b4cd80b03389 ("mptcp: pm: Fix uaf in __timer_delete_sync"), commit d88c476f4a7d ("mptcp: export lookup_anno_list_by_saddr") and commit d58300c3185b ("mptcp: validate 'id' when stopping the ADD_ADDR retransmit timer") look safe to be backported as well, even if there was one small conflict, but easy to resolve. The first one is a refactoring, while the second one is a fix that is helping to prevent the new issues being fixed here.
Davide Caratti (1): mptcp: validate 'id' when stopping the ADD_ADDR retransmit timer
Edward Adam Davis (1): mptcp: pm: Fix uaf in __timer_delete_sync
Geliang Tang (1): mptcp: export lookup_anno_list_by_saddr
net/mptcp/options.c | 2 +- net/mptcp/pm_netlink.c | 27 ++++++++++++++++----------- net/mptcp/protocol.h | 5 ++++- 3 files changed, 21 insertions(+), 13 deletions(-)
From: Geliang Tang geliangtang@gmail.com
commit d88c476f4a7dd69a2588470f6c4f8b663efa16c6 upstream.
This patch exported the static function lookup_anno_list_by_saddr, and renamed it to mptcp_lookup_anno_list_by_saddr.
Signed-off-by: Geliang Tang geliangtang@gmail.com Signed-off-by: Mat Martineau mathew.j.martineau@linux.intel.com Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: b4cd80b03389 ("mptcp: pm: Fix uaf in __timer_delete_sync") Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/pm_netlink.c | 10 +++++----- net/mptcp/protocol.h | 3 +++ 2 files changed, 8 insertions(+), 5 deletions(-)
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index f115c92c45d4..0b566678cc96 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -194,9 +194,9 @@ static void check_work_pending(struct mptcp_sock *msk) WRITE_ONCE(msk->pm.work_pending, false); }
-static struct mptcp_pm_add_entry * -lookup_anno_list_by_saddr(struct mptcp_sock *msk, - struct mptcp_addr_info *addr) +struct mptcp_pm_add_entry * +mptcp_lookup_anno_list_by_saddr(struct mptcp_sock *msk, + struct mptcp_addr_info *addr) { struct mptcp_pm_add_entry *entry;
@@ -255,7 +255,7 @@ mptcp_pm_del_add_timer(struct mptcp_sock *msk, struct sock *sk = (struct sock *)msk;
spin_lock_bh(&msk->pm.lock); - entry = lookup_anno_list_by_saddr(msk, addr); + entry = mptcp_lookup_anno_list_by_saddr(msk, addr); if (entry) entry->retrans_times = ADD_ADDR_RETRANS_MAX; spin_unlock_bh(&msk->pm.lock); @@ -272,7 +272,7 @@ static bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk, struct mptcp_pm_add_entry *add_entry = NULL; struct sock *sk = (struct sock *)msk;
- if (lookup_anno_list_by_saddr(msk, &entry->addr)) + if (mptcp_lookup_anno_list_by_saddr(msk, &entry->addr)) return false;
add_entry = kmalloc(sizeof(*add_entry), GFP_ATOMIC); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index b8351b671c2f..eaaff2cee4d5 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -451,6 +451,9 @@ void mptcp_pm_free_anno_list(struct mptcp_sock *msk); struct mptcp_pm_add_entry * mptcp_pm_del_add_timer(struct mptcp_sock *msk, struct mptcp_addr_info *addr); +struct mptcp_pm_add_entry * +mptcp_lookup_anno_list_by_saddr(struct mptcp_sock *msk, + struct mptcp_addr_info *addr);
int mptcp_pm_announce_addr(struct mptcp_sock *msk, const struct mptcp_addr_info *addr,
From: Davide Caratti dcaratti@redhat.com
commit d58300c3185b78ab910092488126b97f0abe3ae2 upstream.
when Linux receives an echo-ed ADD_ADDR, it checks the IP address against the list of "announced" addresses. In case of a positive match, the timer that handles retransmissions is stopped regardless of the 'Address Id' in the received packet: this behaviour does not comply with RFC8684 3.4.1.
Fix it by validating the 'Address Id' in received echo-ed ADD_ADDRs. Tested using packetdrill, with the following captured output:
unpatched kernel:
Out <...> Flags [.], ack 1, win 256, options [mptcp add-addr v1 id 1 198.51.100.2 hmac 0xfd2e62517888fe29,mptcp dss ack 3007449509], length 0 In <...> Flags [.], ack 1, win 257, options [mptcp add-addr v1-echo id 1 1.2.3.4,mptcp dss ack 3013740213], length 0 Out <...> Flags [.], ack 1, win 256, options [mptcp add-addr v1 id 1 198.51.100.2 hmac 0xfd2e62517888fe29,mptcp dss ack 3007449509], length 0 In <...> Flags [.], ack 1, win 257, options [mptcp add-addr v1-echo id 90 198.51.100.2,mptcp dss ack 3013740213], length 0 ^^^ retransmission is stopped here, but 'Address Id' is 90
patched kernel:
Out <...> Flags [.], ack 1, win 256, options [mptcp add-addr v1 id 1 198.51.100.2 hmac 0x1cf372d59e05f4b8,mptcp dss ack 3007449509], length 0 In <...> Flags [.], ack 1, win 257, options [mptcp add-addr v1-echo id 1 1.2.3.4,mptcp dss ack 1672384568], length 0 Out <...> Flags [.], ack 1, win 256, options [mptcp add-addr v1 id 1 198.51.100.2 hmac 0x1cf372d59e05f4b8,mptcp dss ack 3007449509], length 0 In <...> Flags [.], ack 1, win 257, options [mptcp add-addr v1-echo id 90 198.51.100.2,mptcp dss ack 1672384568], length 0 Out <...> Flags [.], ack 1, win 256, options [mptcp add-addr v1 id 1 198.51.100.2 hmac 0x1cf372d59e05f4b8,mptcp dss ack 3007449509], length 0 In <...> Flags [.], ack 1, win 257, options [mptcp add-addr v1-echo id 1 198.51.100.2,mptcp dss ack 1672384568], length 0 ^^^ retransmission is stopped here, only when both 'Address Id' and 'IP Address' match
Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout") Signed-off-by: Davide Caratti dcaratti@redhat.com Signed-off-by: Mat Martineau mathew.j.martineau@linux.intel.com Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: b4cd80b03389 ("mptcp: pm: Fix uaf in __timer_delete_sync") [ Conflicts in options.c, because some features are missing in this version, e.g. commit 557963c383e8 ("mptcp: move to next addr when subflow creation fail") and commit f7dafee18538 ("mptcp: use mptcp_addr_info in mptcp_options_received"). ] Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/options.c | 2 +- net/mptcp/pm_netlink.c | 8 ++++---- net/mptcp/protocol.h | 2 +- 3 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 9b11396552df..8bc8812f7526 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -915,7 +915,7 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) mptcp_pm_add_addr_received(msk, &addr); MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ADDADDR); } else { - mptcp_pm_del_add_timer(msk, &addr); + mptcp_pm_del_add_timer(msk, &addr, true); MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ECHOADD); } mp_opt.add_addr = 0; diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 0b566678cc96..f4f5cc76870a 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -249,18 +249,18 @@ static void mptcp_pm_add_timer(struct timer_list *timer)
struct mptcp_pm_add_entry * mptcp_pm_del_add_timer(struct mptcp_sock *msk, - struct mptcp_addr_info *addr) + struct mptcp_addr_info *addr, bool check_id) { struct mptcp_pm_add_entry *entry; struct sock *sk = (struct sock *)msk;
spin_lock_bh(&msk->pm.lock); entry = mptcp_lookup_anno_list_by_saddr(msk, addr); - if (entry) + if (entry && (!check_id || entry->addr.id == addr->id)) entry->retrans_times = ADD_ADDR_RETRANS_MAX; spin_unlock_bh(&msk->pm.lock);
- if (entry) + if (entry && (!check_id || entry->addr.id == addr->id)) sk_stop_timer_sync(sk, &entry->add_timer);
return entry; @@ -764,7 +764,7 @@ static bool remove_anno_list_by_saddr(struct mptcp_sock *msk, { struct mptcp_pm_add_entry *entry;
- entry = mptcp_pm_del_add_timer(msk, addr); + entry = mptcp_pm_del_add_timer(msk, addr, false); if (entry) { list_del(&entry->list); kfree(entry); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index eaaff2cee4d5..44944e8f73c5 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -450,7 +450,7 @@ void mptcp_pm_rm_addr_received(struct mptcp_sock *msk, u8 rm_id); void mptcp_pm_free_anno_list(struct mptcp_sock *msk); struct mptcp_pm_add_entry * mptcp_pm_del_add_timer(struct mptcp_sock *msk, - struct mptcp_addr_info *addr); + struct mptcp_addr_info *addr, bool check_id); struct mptcp_pm_add_entry * mptcp_lookup_anno_list_by_saddr(struct mptcp_sock *msk, struct mptcp_addr_info *addr);
From: Edward Adam Davis eadavis@qq.com
There are two paths to access mptcp_pm_del_add_timer, result in a race condition:
CPU1 CPU2 ==== ==== net_rx_action napi_poll netlink_sendmsg __napi_poll netlink_unicast process_backlog netlink_unicast_kernel __netif_receive_skb genl_rcv __netif_receive_skb_one_core netlink_rcv_skb NF_HOOK genl_rcv_msg ip_local_deliver_finish genl_family_rcv_msg ip_protocol_deliver_rcu genl_family_rcv_msg_doit tcp_v4_rcv mptcp_pm_nl_flush_addrs_doit tcp_v4_do_rcv mptcp_nl_remove_addrs_list tcp_rcv_established mptcp_pm_remove_addrs_and_subflows tcp_data_queue remove_anno_list_by_saddr mptcp_incoming_options mptcp_pm_del_add_timer mptcp_pm_del_add_timer kfree(entry)
In remove_anno_list_by_saddr(running on CPU2), after leaving the critical zone protected by "pm.lock", the entry will be released, which leads to the occurrence of uaf in the mptcp_pm_del_add_timer(running on CPU1).
Keeping a reference to add_timer inside the lock, and calling sk_stop_timer_sync() with this reference, instead of "entry->add_timer".
Move list_del(&entry->list) to mptcp_pm_del_add_timer and inside the pm lock, do not directly access any members of the entry outside the pm lock, which can avoid similar "entry->x" uaf.
Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout") Cc: stable@vger.kernel.org Reported-and-tested-by: syzbot+f3a31fb909db9b2a5c4d@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f3a31fb909db9b2a5c4d Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org Signed-off-by: Edward Adam Davis eadavis@qq.com Acked-by: Paolo Abeni pabeni@redhat.com Link: https://patch.msgid.link/tencent_7142963A37944B4A74EF76CD66EA3C253609@qq.com Signed-off-by: Jakub Kicinski kuba@kernel.org (cherry picked from commit b4cd80b0338945a94972ac3ed54f8338d2da2076) Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/pm_netlink.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index f4f5cc76870a..bd03fb6df729 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -253,15 +253,21 @@ mptcp_pm_del_add_timer(struct mptcp_sock *msk, { struct mptcp_pm_add_entry *entry; struct sock *sk = (struct sock *)msk; + struct timer_list *add_timer = NULL;
spin_lock_bh(&msk->pm.lock); entry = mptcp_lookup_anno_list_by_saddr(msk, addr); - if (entry && (!check_id || entry->addr.id == addr->id)) + if (entry && (!check_id || entry->addr.id == addr->id)) { entry->retrans_times = ADD_ADDR_RETRANS_MAX; + add_timer = &entry->add_timer; + } + if (!check_id && entry) + list_del(&entry->list); spin_unlock_bh(&msk->pm.lock);
- if (entry && (!check_id || entry->addr.id == addr->id)) - sk_stop_timer_sync(sk, &entry->add_timer); + /* no lock, because sk_stop_timer_sync() is calling del_timer_sync() */ + if (add_timer) + sk_stop_timer_sync(sk, add_timer);
return entry; } @@ -766,7 +772,6 @@ static bool remove_anno_list_by_saddr(struct mptcp_sock *msk,
entry = mptcp_pm_del_add_timer(msk, addr, false); if (entry) { - list_del(&entry->list); kfree(entry); return true; }
linux-stable-mirror@lists.linaro.org
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gregkh＠linuxfoundation.org -
Matthieu Baerts (NGI0)