August 2019 - Linux-stable-mirror

[PATCH] loop: avoid EAGAIN, if offset or block_size are changed

by Jaegeuk Kim

This patch tries to avoid EAGAIN due to nrpages!=0 that was originally trying to drop stale pages resulting in wrong data access. Report: https://bugs.chromium.org/p/chromium/issues/detail?id=938958#c38 Cc: <stable(a)vger.kernel.org> Cc: Jens Axboe <axboe(a)kernel.dk> Cc: linux-block(a)vger.kernel.org Cc: Bart Van Assche <bvanassche(a)acm.org> Fixes: 5db470e229e2 ("loop: drop caches if offset or block_size are changed") Reported-by: Gwendal Grignou <gwendal(a)chromium.org> Reported-by: grygorii tertychnyi <gtertych(a)cisco.com> Signed-off-by: Jaegeuk Kim <jaegeuk(a)kernel.org> --- drivers/block/loop.c | 44 +++++++++++++++++--------------------------- 1 file changed, 17 insertions(+), 27 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 102d79575895..7c7d2d9c47d0 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1212,6 +1212,7 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) kuid_t uid = current_uid(); struct block_device *bdev; bool partscan = false; + bool drop_caches = false; err = mutex_lock_killable(&loop_ctl_mutex); if (err) @@ -1232,10 +1233,8 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) } if (lo->lo_offset != info->lo_offset || - lo->lo_sizelimit != info->lo_sizelimit) { - sync_blockdev(lo->lo_device); - kill_bdev(lo->lo_device); - } + lo->lo_sizelimit != info->lo_sizelimit) + drop_caches = true; /* I/O need to be drained during transfer transition */ blk_mq_freeze_queue(lo->lo_queue); @@ -1265,14 +1264,6 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) if (lo->lo_offset != info->lo_offset || lo->lo_sizelimit != info->lo_sizelimit) { - /* kill_bdev should have truncated all the pages */ - if (lo->lo_device->bd_inode->i_mapping->nrpages) { - err = -EAGAIN; - pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n", - __func__, lo->lo_number, lo->lo_file_name, - lo->lo_device->bd_inode->i_mapping->nrpages); - goto out_unfreeze; - } if (figure_loop_size(lo, info->lo_offset, info->lo_sizelimit)) { err = -EFBIG; goto out_unfreeze; @@ -1317,6 +1308,12 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) bdev = lo->lo_device; partscan = true; } + + /* truncate stale pages cached by previous operations */ + if (!err && drop_caches) { + sync_blockdev(lo->lo_device); + kill_bdev(lo->lo_device); + } out_unlock: mutex_unlock(&loop_ctl_mutex); if (partscan) @@ -1498,6 +1495,7 @@ static int loop_set_dio(struct loop_device *lo, unsigned long arg) static int loop_set_block_size(struct loop_device *lo, unsigned long arg) { + bool drop_caches = false; int err = 0; if (lo->lo_state != Lo_bound) @@ -1506,23 +1504,10 @@ static int loop_set_block_size(struct loop_device *lo, unsigned long arg) if (arg < 512 || arg > PAGE_SIZE || !is_power_of_2(arg)) return -EINVAL; - if (lo->lo_queue->limits.logical_block_size != arg) { - sync_blockdev(lo->lo_device); - kill_bdev(lo->lo_device); - } + if (lo->lo_queue->limits.logical_block_size != arg) + drop_caches = true; blk_mq_freeze_queue(lo->lo_queue); - - /* kill_bdev should have truncated all the pages */ - if (lo->lo_queue->limits.logical_block_size != arg && - lo->lo_device->bd_inode->i_mapping->nrpages) { - err = -EAGAIN; - pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n", - __func__, lo->lo_number, lo->lo_file_name, - lo->lo_device->bd_inode->i_mapping->nrpages); - goto out_unfreeze; - } - blk_queue_logical_block_size(lo->lo_queue, arg); blk_queue_physical_block_size(lo->lo_queue, arg); blk_queue_io_min(lo->lo_queue, arg); @@ -1530,6 +1515,11 @@ static int loop_set_block_size(struct loop_device *lo, unsigned long arg) out_unfreeze: blk_mq_unfreeze_queue(lo->lo_queue); + /* truncate stale pages cached by previous operations */ + if (drop_caches) { + sync_blockdev(lo->lo_device); + kill_bdev(lo->lo_device); + } return err; } -- 2.19.0.605.g01d371f741-goog

4 years, 2 months

6
13
0 0

[PATCH] jffs2: Fix integer underflow in jffs2_rtime_compress

by Richard Weinberger

The rtime compressor assumes that at least two bytes are compressed. If we try to compress just one byte, the loop condition will wrap around and an out-of-bounds write happens. Cc: <stable(a)vger.kernel.org> Signed-off-by: Richard Weinberger <richard(a)nod.at> --- fs/jffs2/compr_rtime.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/jffs2/compr_rtime.c b/fs/jffs2/compr_rtime.c index 406d9cc84ba8..cbf700001fc9 100644 --- a/fs/jffs2/compr_rtime.c +++ b/fs/jffs2/compr_rtime.c @@ -39,6 +39,9 @@ static int jffs2_rtime_compress(unsigned char *data_in, memset(positions,0,sizeof(positions)); + if (*dstlen < 2) + return -1; + while (pos < (*sourcelen) && outpos <= (*dstlen)-2) { int backpos, runlen=0; unsigned char value; -- 2.20.0

4 years, 3 months

2
3
0 0

Back-porting request

by Stephen Suryaputra

Hello, I'm requesting this commit to be back-ported to v4.14: --- commit 5b18f1289808fee5d04a7e6ecf200189f41a4db6 Author: Stephen Suryaputra <ssuryaextr(a)gmail.com> Date: Wed Jun 26 02:21:16 2019 -0400 ipv4: reset rt_iif for recirculated mcast/bcast out pkts Multicast or broadcast egress packets have rt_iif set to the oif. These packets might be recirculated back as input and lookup to the raw sockets may fail because they are bound to the incoming interface (skb_iif). If rt_iif is not zero, during the lookup, inet_iif() function returns rt_iif instead of skb_iif. Hence, the lookup fails. v2: Make it non vrf specific (David Ahern). Reword the changelog to reflect it. Signed-off-by: Stephen Suryaputra <ssuryaextr(a)gmail.com> Reviewed-by: David Ahern <dsahern(a)gmail.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> --- We found the issue in that release and the above commit is on linux-stable. On the discussion behind this commit, please see: https://www.spinics.net/lists/netdev/msg581045.html I think after the following diff is needed on top of the above commit for v4.14: --- diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 4d85a4fdfdb0..ad2718c1624e 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1623,11 +1623,8 @@ struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) new_rt->rt_iif = rt->rt_iif; new_rt->rt_pmtu = rt->rt_pmtu; new_rt->rt_mtu_locked = rt->rt_mtu_locked; - new_rt->rt_gw_family = rt->rt_gw_family; - if (rt->rt_gw_family == AF_INET) - new_rt->rt_gw4 = rt->rt_gw4; - else if (rt->rt_gw_family == AF_INET6) - new_rt->rt_gw6 = rt->rt_gw6; + new_rt->rt_gateway = rt->rt_gateway; + new_rt->rt_table_id = rt->rt_table_id; INIT_LIST_HEAD(&new_rt->rt_uncached); new_rt->dst.flags |= DST_HOST; --- Thank you, Stephen.

4 years, 5 months

4
3
0 0

[PATCH 4.9 00/42] 4.9.188-stable review

by Greg Kroah-Hartman

This is the start of the stable review cycle for the 4.9.188 release. There are 42 patches in this series, all will be posted as a response to this one. If anyone has any issues with these being applied, please let me know. Responses should be made by Wed 07 Aug 2019 12:47:58 PM UTC. Anything received after that time might be too late. The whole patch series can be found in one patch at: https://www.kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.9.188-rc… or in the git tree and branch at: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.9.y and the diffstat can be found below. thanks, greg k-h ------------- Pseudo-Shortlog of commits: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Linux 4.9.188-rc1 Vlastimil Babka <vbabka(a)suse.cz> x86, mm, gup: prevent get_page() race with munmap in paravirt guest Josh Poimboeuf <jpoimboe(a)redhat.com> objtool: Support GCC 9 cold subfunction naming scheme Miguel Ojeda <miguel.ojeda.sandonis(a)gmail.com> include/linux/module.h: copy __init/__exit attrs to init/cleanup_module Miguel Ojeda <miguel.ojeda.sandonis(a)gmail.com> Backport minimal compiler_attributes.h to support GCC 9 Jean Delvare <jdelvare(a)suse.de> eeprom: at24: make spd world-readable again Andrea Arcangeli <aarcange(a)redhat.com> coredump: fix race condition between collapse_huge_page() and core dumping Ajay Kaher <akaher(a)vmware.com> infiniband: fix race condition between infiniband mlx4, mlx5 driver and core dumping Andrea Arcangeli <aarcange(a)redhat.com> coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping Yishai Hadas <yishaih(a)mellanox.com> IB/mlx5: Fix RSS Toeplitz setup to be aligned with the HW specification Juergen Gross <jgross(a)suse.com> xen/swiotlb: fix condition for calling xen_destroy_contiguous_region() Will Deacon <will(a)kernel.org> drivers/perf: arm_pmu: Fix failure path in PM notifier Stefan Haberland <sth(a)linux.ibm.com> s390/dasd: fix endless loop after read unit address configuration Ondrej Mosnacek <omosnace(a)redhat.com> selinux: fix memory leak in policydb_init() Michael Wu <michael.wu(a)vatics.com> gpiolib: fix incorrect IRQ requesting of an active-low lineevent Douglas Anderson <dianders(a)chromium.org> mmc: dw_mmc: Fix occasional hang after tuning on eMMC Filipe Manana <fdmanana(a)suse.com> Btrfs: fix incremental send failure after deduplication Masahiro Yamada <yamada.masahiro(a)socionext.com> kbuild: initialize CLANG_FLAGS correctly in the top Makefile Zhenzhong Duan <zhenzhong.duan(a)oracle.com> x86, boot: Remove multiple copy of static function sanitize_boot_params() Josh Poimboeuf <jpoimboe(a)redhat.com> x86/kvm: Don't call kvm_spurious_fault() from .fixup Kees Cook <keescook(a)chromium.org> ipc/mqueue.c: only perform resource calculation if user valid Dan Carpenter <dan.carpenter(a)oracle.com> drivers/rapidio/devices/rio_mport_cdev.c: NUL terminate some strings Mikko Rapeli <mikko.rapeli(a)iki.fi> uapi linux/coda_psdev.h: move upc_req definition from uapi to kernel side headers Sam Protsenko <semen.protsenko(a)linaro.org> coda: fix build using bare-metal toolchain Zhouyang Jia <jiazhouyang09(a)gmail.com> coda: add error handling for fget Doug Berger <opendmb(a)gmail.com> mm/cma.c: fail if fixed declaration can't be honored Arnd Bergmann <arnd(a)arndb.de> x86: math-emu: Hide clang warnings for 16-bit overflow Qian Cai <cai(a)lca.pw> x86/apic: Silence -Wtype-limits compiler warnings Benjamin Poirier <bpoirier(a)suse.com> be2net: Signal that the device cannot transmit during reconfiguration Arnd Bergmann <arnd(a)arndb.de> ACPI: fix false-positive -Wuninitialized warning Benjamin Block <bblock(a)linux.ibm.com> scsi: zfcp: fix GCC compiler warning emitted with -Wmaybe-uninitialized Jeff Layton <jlayton(a)kernel.org> ceph: return -ERANGE if virtual xattr value didn't fit in buffer Andrea Parri <andrea.parri(a)amarulasolutions.com> ceph: fix improper use of smp_mb__before_atomic() David Sterba <dsterba(a)suse.com> btrfs: fix minimum number of chunk errors for DUP Russell King <rmk+kernel(a)armlinux.org.uk> fs/adfs: super: fix use-after-free bug Geert Uytterhoeven <geert+renesas(a)glider.be> dmaengine: rcar-dmac: Reject zero-length slave DMA requests Petr Cvek <petrcvekcz(a)gmail.com> MIPS: lantiq: Fix bitfield masking Prarit Bhargava <prarit(a)redhat.com> kernel/module.c: Only return -EEXIST for modules that have finished loading Cheng Jian <cj.chengjian(a)huawei.com> ftrace: Enable trampoline when rec count returns back to one Douglas Anderson <dianders(a)chromium.org> ARM: dts: rockchip: Mark that the rk3288 timer might stop in suspend Douglas Anderson <dianders(a)chromium.org> ARM: dts: rockchip: Make rk3288-veyron-mickey's emmc work again Douglas Anderson <dianders(a)chromium.org> ARM: dts: rockchip: Make rk3288-veyron-minnie run at hs200 Russell King <rmk+kernel(a)armlinux.org.uk> ARM: riscpc: fix DMA ------------- Diffstat: Makefile | 7 +-- arch/arm/boot/dts/rk3288-veyron-mickey.dts | 4 -- arch/arm/boot/dts/rk3288-veyron-minnie.dts | 4 -- arch/arm/boot/dts/rk3288.dtsi | 1 + arch/arm/mach-rpc/dma.c | 5 +- arch/mips/lantiq/irq.c | 5 +- arch/x86/boot/compressed/misc.c | 1 + arch/x86/boot/compressed/misc.h | 1 - arch/x86/include/asm/apic.h | 2 +- arch/x86/include/asm/kvm_host.h | 34 +++++++------ arch/x86/kernel/apic/apic.c | 2 +- arch/x86/math-emu/fpu_emu.h | 2 +- arch/x86/math-emu/reg_constant.c | 2 +- arch/x86/mm/gup.c | 32 +++++++++++- drivers/android/binder.c | 6 +++ drivers/dma/sh/rcar-dmac.c | 2 +- drivers/gpio/gpiolib.c | 6 ++- drivers/infiniband/hw/mlx4/main.c | 4 +- drivers/infiniband/hw/mlx5/main.c | 3 ++ drivers/infiniband/hw/mlx5/qp.c | 1 - drivers/misc/eeprom/at24.c | 2 +- drivers/mmc/host/dw_mmc.c | 3 +- drivers/net/ethernet/emulex/benet/be_main.c | 6 ++- drivers/perf/arm_pmu.c | 2 +- drivers/rapidio/devices/rio_mport_cdev.c | 2 + drivers/s390/block/dasd_alias.c | 22 ++++++--- drivers/s390/scsi/zfcp_erp.c | 7 +++ drivers/xen/swiotlb-xen.c | 4 +- fs/adfs/super.c | 5 +- fs/btrfs/send.c | 77 ++++++----------------------- fs/btrfs/volumes.c | 3 +- fs/ceph/super.h | 7 ++- fs/ceph/xattr.c | 14 +++--- fs/coda/psdev.c | 5 +- fs/proc/task_mmu.c | 18 +++++++ fs/userfaultfd.c | 9 ++++ include/linux/acpi.h | 5 +- include/linux/coda.h | 3 +- include/linux/coda_psdev.h | 11 +++++ include/linux/compiler.h | 16 ++++++ include/linux/mm.h | 24 +++++++++ include/linux/module.h | 4 +- include/uapi/linux/coda_psdev.h | 13 ----- ipc/mqueue.c | 19 +++---- kernel/module.c | 6 +-- kernel/trace/ftrace.c | 28 ++++++----- mm/cma.c | 13 +++++ mm/khugepaged.c | 3 ++ mm/mmap.c | 6 ++- security/selinux/ss/policydb.c | 6 ++- tools/objtool/elf.c | 2 +- 51 files changed, 294 insertions(+), 175 deletions(-)

4 years, 5 months

7
53
0 0

[PATCH AUTOSEL 4.20 001/117] netfilter: ipset: Allow matching on destination MAC address for mac and ipmac sets

by Sasha Levin

From: Stefano Brivio <sbrivio(a)redhat.com> [ Upstream commit 8cc4ccf58379935f3ad456cc34e61c4e4c921d0e ] There doesn't seem to be any reason to restrict MAC address matching to source MAC addresses in set types bitmap:ipmac, hash:ipmac and hash:mac. With this patch, and this setup: ip netns add A ip link add veth1 type veth peer name veth2 netns A ip addr add 192.0.2.1/24 dev veth1 ip -net A addr add 192.0.2.2/24 dev veth2 ip link set veth1 up ip -net A link set veth2 up ip netns exec A ipset create test hash:mac dst=$(ip netns exec A cat /sys/class/net/veth2/address) ip netns exec A ipset add test ${dst} ip netns exec A iptables -P INPUT DROP ip netns exec A iptables -I INPUT -m set --match-set test dst -j ACCEPT ipset will match packets based on destination MAC address: # ping -c1 192.0.2.2 >/dev/null # echo $? 0 Reported-by: Yi Chen <yiche(a)redhat.com> Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com> Signed-off-by: Jozsef Kadlecsik <kadlec(a)blackhole.kfki.hu> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- net/netfilter/ipset/ip_set_bitmap_ipmac.c | 10 +++++----- net/netfilter/ipset/ip_set_hash_ipmac.c | 16 ++++++++++------ net/netfilter/ipset/ip_set_hash_mac.c | 10 +++++----- 3 files changed, 20 insertions(+), 16 deletions(-) diff --git a/net/netfilter/ipset/ip_set_bitmap_ipmac.c b/net/netfilter/ipset/ip_set_bitmap_ipmac.c index c00b6a2e8e3c..13ade5782847 100644 --- a/net/netfilter/ipset/ip_set_bitmap_ipmac.c +++ b/net/netfilter/ipset/ip_set_bitmap_ipmac.c @@ -219,10 +219,6 @@ bitmap_ipmac_kadt(struct ip_set *set, const struct sk_buff *skb, struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set); u32 ip; - /* MAC can be src only */ - if (!(opt->flags & IPSET_DIM_TWO_SRC)) - return 0; - ip = ntohl(ip4addr(skb, opt->flags & IPSET_DIM_ONE_SRC)); if (ip < map->first_ip || ip > map->last_ip) return -IPSET_ERR_BITMAP_RANGE; @@ -233,7 +229,11 @@ bitmap_ipmac_kadt(struct ip_set *set, const struct sk_buff *skb, return -EINVAL; e.id = ip_to_id(map, ip); - memcpy(e.ether, eth_hdr(skb)->h_source, ETH_ALEN); + + if (opt->flags & IPSET_DIM_ONE_SRC) + ether_addr_copy(e.ether, eth_hdr(skb)->h_source); + else + ether_addr_copy(e.ether, eth_hdr(skb)->h_dest); return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags); } diff --git a/net/netfilter/ipset/ip_set_hash_ipmac.c b/net/netfilter/ipset/ip_set_hash_ipmac.c index 1ab5ed2f6839..fd87de3ed55b 100644 --- a/net/netfilter/ipset/ip_set_hash_ipmac.c +++ b/net/netfilter/ipset/ip_set_hash_ipmac.c @@ -103,7 +103,11 @@ hash_ipmac4_kadt(struct ip_set *set, const struct sk_buff *skb, (skb_mac_header(skb) + ETH_HLEN) > skb->data) return -EINVAL; - memcpy(e.ether, eth_hdr(skb)->h_source, ETH_ALEN); + if (opt->flags & IPSET_DIM_ONE_SRC) + ether_addr_copy(e.ether, eth_hdr(skb)->h_source); + else + ether_addr_copy(e.ether, eth_hdr(skb)->h_dest); + if (ether_addr_equal(e.ether, invalid_ether)) return -EINVAL; @@ -211,15 +215,15 @@ hash_ipmac6_kadt(struct ip_set *set, const struct sk_buff *skb, }; struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set); - /* MAC can be src only */ - if (!(opt->flags & IPSET_DIM_TWO_SRC)) - return 0; - if (skb_mac_header(skb) < skb->head || (skb_mac_header(skb) + ETH_HLEN) > skb->data) return -EINVAL; - memcpy(e.ether, eth_hdr(skb)->h_source, ETH_ALEN); + if (opt->flags & IPSET_DIM_ONE_SRC) + ether_addr_copy(e.ether, eth_hdr(skb)->h_source); + else + ether_addr_copy(e.ether, eth_hdr(skb)->h_dest); + if (ether_addr_equal(e.ether, invalid_ether)) return -EINVAL; diff --git a/net/netfilter/ipset/ip_set_hash_mac.c b/net/netfilter/ipset/ip_set_hash_mac.c index f9d5a2a1e3d0..4fe5f243d0a3 100644 --- a/net/netfilter/ipset/ip_set_hash_mac.c +++ b/net/netfilter/ipset/ip_set_hash_mac.c @@ -81,15 +81,15 @@ hash_mac4_kadt(struct ip_set *set, const struct sk_buff *skb, struct hash_mac4_elem e = { { .foo[0] = 0, .foo[1] = 0 } }; struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set); - /* MAC can be src only */ - if (!(opt->flags & IPSET_DIM_ONE_SRC)) - return 0; - if (skb_mac_header(skb) < skb->head || (skb_mac_header(skb) + ETH_HLEN) > skb->data) return -EINVAL; - ether_addr_copy(e.ether, eth_hdr(skb)->h_source); + if (opt->flags & IPSET_DIM_ONE_SRC) + ether_addr_copy(e.ether, eth_hdr(skb)->h_source); + else + ether_addr_copy(e.ether, eth_hdr(skb)->h_dest); + if (is_zero_ether_addr(e.ether)) return -EINVAL; return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags); -- 2.19.1

4 years, 5 months

10
134
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Fix bad backport to stable v3.16+

by Song Liu

Hi, As reported by Thorsten Knabe <linux(a)thorsten-knabe.de>. commit 4f4fd7c5798b ("Don't jump to compute_result state from check_result state") was back ported to v3.16+. However, this fix was wrong. Please back port the following two commits to fix this issue. commit a25d8c327bb4 ("Revert "Don't jump to compute_result state from check_result state"") commit b2176a1dfb51 ("md/raid: raid5 preserve the writeback action after the parity check") Thanks, Song

4 years, 5 months

3
3
0 0

[PATCH 4/4] drm/i915: Flush stale cachelines on set-cache-level

by Chris Wilson

Ensure that we flush any cache dirt out to main memory before the user changes the cache-level as they may elect to bypass the cache (even after declaring their access cache-coherent) via use of unprivileged MOCS. Signed-off-by: Chris Wilson <chris(a)chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen(a)linux.intel.com> Cc: stable(a)vger.kernel.org --- drivers/gpu/drm/i915/gem/i915_gem_domain.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_domain.c b/drivers/gpu/drm/i915/gem/i915_gem_domain.c index 2e3ce2a69653..5d41e769a428 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_domain.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_domain.c @@ -277,6 +277,11 @@ int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj, list_for_each_entry(vma, &obj->vma.list, obj_link) vma->node.color = cache_level; + + /* Flush any previous cache dirt in case of cache bypass */ + if (obj->cache_dirty & ~obj->cache_coherent) + i915_gem_clflush_object(obj, I915_CLFLUSH_SYNC); + i915_gem_object_set_cache_coherency(obj, cache_level); obj->cache_dirty = true; /* Always invalidate stale cachelines */ -- 2.22.0

4 years, 5 months

3
5
0 0

[PATCH STABLE 4.9] x86, mm, gup: prevent get_page() race with munmap in paravirt guest

by Vlastimil Babka

The x86 version of get_user_pages_fast() relies on disabled interrupts to synchronize gup_pte_range() between gup_get_pte(ptep); and get_page() against a parallel munmap. The munmap side nulls the pte, then flushes TLBs, then releases the page. As TLB flush is done synchronously via IPI disabling interrupts blocks the page release, and get_page(), which assumes existing reference on page, is thus safe. However when TLB flush is done by a hypercall, e.g. in a Xen PV guest, there is no blocking thanks to disabled interrupts, and get_page() can succeed on a page that was already freed or even reused. We have recently seen this happen with our 4.4 and 4.12 based kernels, with userspace (java) that exits a thread, where mm_release() performs a futex_wake() on tsk->clear_child_tid, and another thread in parallel unmaps the page where tsk->clear_child_tid points to. The spurious get_page() succeeds, but futex code immediately releases the page again, while it's already on a freelist. Symptoms include a bad page state warning, general protection faults acessing a poisoned list prev/next pointer in the freelist, or free page pcplists of two cpus joined together in a single list. Oscar has also reproduced this scenario, with a patch inserting delays before the get_page() to make the race window larger. Fix this by removing the dependency on TLB flush interrupts the same way as the generic get_user_pages_fast() code by using page_cache_add_speculative() and revalidating the PTE contents after pinning the page. Mainline is safe since 4.13 where the x86 gup code was removed in favor of the common code. Accessing the page table itself safely also relies on disabled interrupts and TLB flush IPIs that don't happen with hypercalls, which was acknowledged in commit 9e52fc2b50de ("x86/mm: Enable RCU based page table freeing (CONFIG_HAVE_RCU_TABLE_FREE=y)"). That commit with follups should also be backported for full safety, although our reproducer didn't hit a problem without that backport. Reproduced-by: Oscar Salvador <osalvador(a)suse.de> Signed-off-by: Vlastimil Babka <vbabka(a)suse.cz> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Juergen Gross <jgross(a)suse.com> Cc: Kirill A. Shutemov <kirill.shutemov(a)linux.intel.com> Cc: Vitaly Kuznetsov <vkuznets(a)redhat.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: Andy Lutomirski <luto(a)kernel.org> --- Hi, I'm sending this stable-only patch for consideration because it's probably unrealistic to backport the 4.13 switch to generic GUP. I can look at 4.4 and 3.16 if accepted. The RCU page table freeing could be also considered. Note the patch also includes page refcount protection. I found out that 8fde12ca79af ("mm: prevent get_user_pages() from overflowing page refcount") backport to 4.9 missed the arch-specific gup implementations: https://lore.kernel.org/lkml/6650323f-dbc9-f069-000b-f6b0f941a065@suse.cz/ arch/x86/mm/gup.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c index 1680768d392c..d7db45bdfb3b 100644 --- a/arch/x86/mm/gup.c +++ b/arch/x86/mm/gup.c @@ -97,6 +97,20 @@ static inline int pte_allows_gup(unsigned long pteval, int write) return 1; } +/* + * Return the compund head page with ref appropriately incremented, + * or NULL if that failed. + */ +static inline struct page *try_get_compound_head(struct page *page, int refs) +{ + struct page *head = compound_head(page); + if (WARN_ON_ONCE(page_ref_count(head) < 0)) + return NULL; + if (unlikely(!page_cache_add_speculative(head, refs))) + return NULL; + return head; +} + /* * The performance critical leaf functions are made noinline otherwise gcc * inlines everything into a single function which results in too much @@ -112,7 +126,7 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr, ptep = pte_offset_map(&pmd, addr); do { pte_t pte = gup_get_pte(ptep); - struct page *page; + struct page *head, *page; /* Similar to the PMD case, NUMA hinting must take slow path */ if (pte_protnone(pte)) { @@ -138,7 +152,21 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr, } VM_BUG_ON(!pfn_valid(pte_pfn(pte))); page = pte_page(pte); - get_page(page); + + head = try_get_compound_head(page, 1); + if (!head) { + put_dev_pagemap(pgmap); + pte_unmap(ptep); + return 0; + } + + if (unlikely(pte_val(pte) != pte_val(*ptep))) { + put_page(head); + put_dev_pagemap(pgmap); + pte_unmap(ptep); + return 0; + } + put_dev_pagemap(pgmap); SetPageReferenced(page); pages[*nr] = page; -- 2.22.0

4 years, 6 months

3
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[PATCH 1/5] drm/i915/userptr: Beware recursive lock_page()

by Chris Wilson

Following a try_to_unmap() we may want to remove the userptr and so call put_pages(). However, try_to_unmap() acquires the page lock and so we must avoid recursively locking the pages ourselves -- which means that we cannot safely acquire the lock around set_page_dirty(). Since we can't be sure of the lock, we have to risk skip dirtying the page, or else risk calling set_page_dirty() without a lock and so risk fs corruption. Reported-by: Lionel Landwerlin <lionel.g.landwerlin(a)intel.com> Fixes: cb6d7c7dc7ff ("drm/i915/userptr: Acquire the page lock around set_page_dirty()") Signed-off-by: Chris Wilson <chris(a)chris-wilson.co.uk> Cc: Lionel Landwerlin <lionel.g.landwerlin(a)intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin(a)intel.com> Cc: stable(a)vger.kernel.org --- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c index b9d2bb15e4a6..1ad2047a6dbd 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -672,7 +672,7 @@ i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj, obj->mm.dirty = false; for_each_sgt_page(page, sgt_iter, pages) { - if (obj->mm.dirty) + if (obj->mm.dirty && trylock_page(page)) { /* * As this may not be anonymous memory (e.g. shmem) * but exist on a real mapping, we have to lock @@ -680,8 +680,20 @@ i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj, * the page reference is not sufficient to * prevent the inode from being truncated. * Play safe and take the lock. + * + * However...! + * + * The mmu-notifier can be invalidated for a + * migrate_page, that is alreadying holding the lock + * on the page. Such a try_to_unmap() will result + * in us calling put_pages() and so recursively try + * to lock the page. We avoid that deadlock with + * a trylock_page() and in exchange we risk missing + * some page dirtying. */ - set_page_dirty_lock(page); + set_page_dirty(page); + unlock_page(page); + } mark_page_accessed(page); put_page(page); -- 2.22.0

4 years, 6 months

3
15
0 0

[PATCH ARM64 v4.4 V3 00/44] V4.4 backport of arm64 Spectre patches

by Viresh Kumar

Hello, This series backports arm64 spectre patches to v4.4 stable kernel. I have started this backport with Mark Rutland's backport of Spectre to 4.9 [1] and tried applying the upstream version of them over 4.4 and resolved conflicts by checking how they have been resolved in 4.9. The KVM changes are mostly dropped as the KVM code in v4.4 is quite different and it makes backport more complex. This was suggested by the ARM team. I had to pick few extra upstream patches to avoid conflicts and to make things work: mm/kasan: add API to check memory regions arm64: kasan: instrument user memory access API arm64: cpufeature: Add scope for capability check arm64: cputype info for Broadcom Vulcan arm64: cputype: Add MIDR values for Cavium ThunderX2 CPUs ARM: 8478/2: arm/arm64: add arm-smccc arm64: cpufeature: Test 'matches' pointer to find the end of the list arm64: Introduce cpu_die_early arm64: Move cpu_die_early to smp.c arm64: Verify CPU errata work arounds on hotplugged CPU arm64: errata: Calling enable functions for CPU errata too arm64: Rearrange CPU errata workaround checks arm64: Add a helper for parking CPUs in a loop I also had to drop few patches as they weren't getting applied properly due to missing files/features or they were KVM related: arm64: cpufeature: __this_cpu_has_cap() shouldn't stop early arm64: KVM: Use per-CPU vector when BP hardening is enabled arm64: KVM: Make PSCI_VERSION a fast path mm: Introduce lm_alias arm64: KVM: Increment PC after handling an SMC trap arm/arm64: KVM: Consolidate the PSCI include files arm/arm64: KVM: Add PSCI_VERSION helper arm/arm64: KVM: Add smccc accessors to PSCI code arm/arm64: KVM: Implement PSCI 1.0 support arm/arm64: KVM: Turn kvm_psci_version into a static inline arm64: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling The patches in this series are pushed here [2]. This is tested on Hikey board (octa A53) and I verified that BP hardening code is getting hit for CPUs (had to hack a bit and enable BP hardening support for A53 for this). V2->V3: - Included an extra patch and used the helper introduced by it: arm64: Add a helper for parking CPUs in a loop - Droped few extra blank lines added by mistake - Avoid overlapping with SVE2 bits V1->V2: - Rebased over 4.4.184 (was 4.4.180 earlier). - Fixed an build issue with CONFIG_KASAN (Julien). - Dropped few patches, mostly KVM stuff (Julien): arm64: remove duplicate macro __KERNEL__ check mm: Introduce lm_alias arm64: KVM: Increment PC after handling an SMC trap arm/arm64: KVM: Consolidate the PSCI include files arm/arm64: KVM: Add PSCI_VERSION helper arm/arm64: KVM: Add smccc accessors to PSCI code arm/arm64: KVM: Implement PSCI 1.0 support arm/arm64: KVM: Turn kvm_psci_version into a static inline arm64: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling - Added few patches to fix issues reported by Julien: arm64: cpufeature: Test 'matches' pointer to find the end of the list arm64: Introduce cpu_die_early arm64: Move cpu_die_early to smp.c arm64: Verify CPU errata work arounds on hotplugged CPU arm64: errata: Calling enable functions for CPU errata too arm64: Rearrange CPU errata workaround checks -- viresh [1] https://patches.linaro.org/cover/133195/ with top commit in 4.9 stable tree: a3b292fe0560 arm64: futex: Mask __user pointers prior to dereference [2] https://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux.git stable/arm64/v4.4.y/spectre -------------------------8<------------------------- Andre Przywara (1): arm64: errata: Calling enable functions for CPU errata too Andrey Ryabinin (1): mm/kasan: add API to check memory regions Catalin Marinas (1): arm64: Factor out TTBR0_EL1 post-update workaround into a specific asm macro James Morse (1): arm64: cpufeature: Test 'matches' pointer to find the end of the list Jayachandran C (3): arm64: cputype info for Broadcom Vulcan arm64: cputype: Add MIDR values for Cavium ThunderX2 CPUs arm64: Branch predictor hardening for Cavium ThunderX2 Jens Wiklander (1): ARM: 8478/2: arm/arm64: add arm-smccc Marc Zyngier (11): arm64: Move post_ttbr_update_workaround to C code arm64: Move BP hardening to check_and_switch_context arm64: cpu_errata: Allow an erratum to be match for all revisions of a core arm/arm64: KVM: Advertise SMCCC v1.1 arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening support firmware/psci: Expose PSCI conduit firmware/psci: Expose SMCCC version through psci_ops arm/arm64: smccc: Make function identifiers an unsigned quantity arm/arm64: smccc: Implement SMCCC v1.1 inline primitive arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support arm64: Kill PSCI_GET_VERSION as a variant-2 workaround Robin Murphy (3): arm64: Implement array_index_mask_nospec() arm64: Make USER_DS an inclusive limit arm64: Use pointer masking to limit uaccess speculation Suzuki K Poulose (7): arm64: cpufeature: Add scope for capability check arm64: Introduce cpu_die_early arm64: Add a helper for parking CPUs in a loop arm64: Move cpu_die_early to smp.c arm64: Verify CPU errata work arounds on hotplugged CPU arm64: Rearrange CPU errata workaround checks arm64: Run enable method for errata work arounds on late CPUs Will Deacon (13): arm64: barrier: Add CSDB macros to control data-value prediction arm64: entry: Ensure branch through syscall table is bounded under speculation arm64: uaccess: Prevent speculative use of the current addr_limit arm64: uaccess: Don't bother eliding access_ok checks in __{get, put}_user arm64: uaccess: Mask __user pointers for __arch_{clear, copy_*}_user arm64: cpufeature: Pass capability structure to ->enable callback drivers/firmware: Expose psci_get_version through psci_ops structure arm64: Add skeleton to harden the branch predictor against aliasing attacks arm64: entry: Apply BP hardening for high-priority synchronous exceptions arm64: entry: Apply BP hardening for suspicious interrupts from EL0 arm64: cputype: Add missing MIDR values for Cortex-A72 and Cortex-A75 arm64: Implement branch predictor hardening for affected Cortex-A CPUs arm64: futex: Mask __user pointers prior to dereference Yang Shi (1): arm64: kasan: instrument user memory access API Yury Norov (1): arm64: move TASK_* definitions to <asm/processor.h> MAINTAINERS | 14 ++ arch/arm64/Kconfig | 17 ++ arch/arm64/include/asm/assembler.h | 18 ++ arch/arm64/include/asm/barrier.h | 23 +++ arch/arm64/include/asm/cpufeature.h | 24 ++- arch/arm64/include/asm/cputype.h | 12 ++ arch/arm64/include/asm/futex.h | 9 +- arch/arm64/include/asm/memory.h | 15 -- arch/arm64/include/asm/mmu.h | 39 ++++ arch/arm64/include/asm/processor.h | 24 +++ arch/arm64/include/asm/smp.h | 9 + arch/arm64/include/asm/sysreg.h | 2 + arch/arm64/include/asm/uaccess.h | 173 ++++++++++++------ arch/arm64/kernel/Makefile | 5 + arch/arm64/kernel/arm64ksyms.c | 8 +- arch/arm64/kernel/bpi.S | 75 ++++++++ arch/arm64/kernel/cpu_errata.c | 213 +++++++++++++++++++++- arch/arm64/kernel/cpufeature.c | 186 +++++++++---------- arch/arm64/kernel/cpuinfo.c | 2 - arch/arm64/kernel/entry.S | 26 ++- arch/arm64/kernel/smp.c | 30 +++- arch/arm64/lib/clear_user.S | 6 +- arch/arm64/lib/copy_from_user.S | 4 +- arch/arm64/lib/copy_in_user.S | 4 +- arch/arm64/lib/copy_to_user.S | 4 +- arch/arm64/mm/context.c | 12 ++ arch/arm64/mm/fault.c | 31 ++++ arch/arm64/mm/proc.S | 12 +- drivers/firmware/Kconfig | 3 + drivers/firmware/psci.c | 58 +++++- include/linux/arm-smccc.h | 267 ++++++++++++++++++++++++++++ include/linux/kasan-checks.h | 12 ++ include/linux/psci.h | 14 ++ mm/kasan/kasan.c | 12 ++ 34 files changed, 1150 insertions(+), 213 deletions(-) create mode 100644 arch/arm64/kernel/bpi.S create mode 100644 include/linux/arm-smccc.h create mode 100644 include/linux/kasan-checks.h -- 2.21.0.rc0.269.g1a574e7a288b

4 years, 6 months

2
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0 0

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Linux-stable-mirror August 2019