https://github.com/torvalds/linux
Revision 6376360ecbe525a9c17b3d081dfd88ba3e4ed65b authored by Naoya Horiguchi on 01 February 2019, 22:21:08 UTC, committed by Linus Torvalds on 01 February 2019, 23:46:23 UTC
Currently memory_failure() is racy against process's exiting, which results in kernel crash by null pointer dereference. The root cause is that memory_failure() uses force_sig() to forcibly kill asynchronous (meaning not in the current context) processes. As discussed in thread https://lkml.org/lkml/2010/6/8/236 years ago for OOM fixes, this is not a right thing to do. OOM solves this issue by using do_send_sig_info() as done in commit d2d393099de2 ("signal: oom_kill_task: use SEND_SIG_FORCED instead of force_sig()"), so this patch is suggesting to do the same for hwpoison. do_send_sig_info() properly accesses to siglock with lock_task_sighand(), so is free from the reported race. I confirmed that the reported bug reproduces with inserting some delay in kill_procs(), and it never reproduces with this patch. Note that memory_failure() can send another type of signal using force_sig_mceerr(), and the reported race shouldn't happen on it because force_sig_mceerr() is called only for synchronous processes (i.e. BUS_MCEERR_AR happens only when some process accesses to the corrupted memory.) Link: http://lkml.kernel.org/r/20190116093046.GA29835@hori1.linux.bs1.fc.nec.co.jp Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reported-by: Jane Chu <jane.chu@oracle.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 0d0c8de
Tip revision: 6376360ecbe525a9c17b3d081dfd88ba3e4ed65b authored by Naoya Horiguchi on 01 February 2019, 22:21:08 UTC
mm: hwpoison: use do_send_sig_info() instead of force_sig()
mm: hwpoison: use do_send_sig_info() instead of force_sig()
Tip revision: 6376360
File | Mode | Size |
---|---|---|
partitions | ||
Kconfig | -rw-r--r-- | 6.5 KB |
Kconfig.iosched | -rw-r--r-- | 1.1 KB |
Makefile | -rw-r--r-- | 1.5 KB |
badblocks.c | -rw-r--r-- | 14.5 KB |
bfq-cgroup.c | -rw-r--r-- | 33.5 KB |
bfq-iosched.c | -rw-r--r-- | 193.2 KB |
bfq-iosched.h | -rw-r--r-- | 34.8 KB |
bfq-wf2q.c | -rw-r--r-- | 52.3 KB |
bio-integrity.c | -rw-r--r-- | 12.9 KB |
bio.c | -rw-r--r-- | 52.3 KB |
blk-cgroup.c | -rw-r--r-- | 46.6 KB |
blk-core.c | -rw-r--r-- | 48.5 KB |
blk-exec.c | -rw-r--r-- | 2.5 KB |
blk-flush.c | -rw-r--r-- | 14.4 KB |
blk-integrity.c | -rw-r--r-- | 12.0 KB |
blk-ioc.c | -rw-r--r-- | 10.2 KB |
blk-iolatency.c | -rw-r--r-- | 27.3 KB |
blk-lib.c | -rw-r--r-- | 10.2 KB |
blk-map.c | -rw-r--r-- | 5.9 KB |
blk-merge.c | -rw-r--r-- | 21.8 KB |
blk-mq-cpumap.c | -rw-r--r-- | 1.7 KB |
blk-mq-debugfs-zoned.c | -rw-r--r-- | 435 bytes |
blk-mq-debugfs.c | -rw-r--r-- | 26.3 KB |
blk-mq-debugfs.h | -rw-r--r-- | 2.7 KB |
blk-mq-pci.c | -rw-r--r-- | 1.7 KB |
blk-mq-rdma.c | -rw-r--r-- | 1.7 KB |
blk-mq-sched.c | -rw-r--r-- | 13.2 KB |
blk-mq-sched.h | -rw-r--r-- | 2.6 KB |
blk-mq-sysfs.c | -rw-r--r-- | 8.4 KB |
blk-mq-tag.c | -rw-r--r-- | 14.5 KB |
blk-mq-tag.h | -rw-r--r-- | 2.3 KB |
blk-mq-virtio.c | -rw-r--r-- | 1.7 KB |
blk-mq.c | -rw-r--r-- | 83.9 KB |
blk-mq.h | -rw-r--r-- | 6.8 KB |
blk-pm.c | -rw-r--r-- | 6.6 KB |
blk-pm.h | -rw-r--r-- | 1.4 KB |
blk-rq-qos.c | -rw-r--r-- | 6.3 KB |
blk-rq-qos.h | -rw-r--r-- | 4.4 KB |
blk-settings.c | -rw-r--r-- | 27.0 KB |
blk-softirq.c | -rw-r--r-- | 3.7 KB |
blk-stat.c | -rw-r--r-- | 4.6 KB |
blk-stat.h | -rw-r--r-- | 4.6 KB |
blk-sysfs.c | -rw-r--r-- | 25.2 KB |
blk-throttle.c | -rw-r--r-- | 67.9 KB |
blk-timeout.c | -rw-r--r-- | 3.7 KB |
blk-wbt.c | -rw-r--r-- | 19.9 KB |
blk-wbt.h | -rw-r--r-- | 3.0 KB |
blk-zoned.c | -rw-r--r-- | 11.7 KB |
blk.h | -rw-r--r-- | 10.1 KB |
bounce.c | -rw-r--r-- | 9.1 KB |
bsg-lib.c | -rw-r--r-- | 9.8 KB |
bsg.c | -rw-r--r-- | 12.5 KB |
cmdline-parser.c | -rw-r--r-- | 4.9 KB |
compat_ioctl.c | -rw-r--r-- | 10.9 KB |
elevator.c | -rw-r--r-- | 16.4 KB |
genhd.c | -rw-r--r-- | 49.5 KB |
ioctl.c | -rw-r--r-- | 15.3 KB |
ioprio.c | -rw-r--r-- | 5.1 KB |
kyber-iosched.c | -rw-r--r-- | 28.3 KB |
mq-deadline.c | -rw-r--r-- | 20.6 KB |
opal_proto.h | -rw-r--r-- | 9.3 KB |
partition-generic.c | -rw-r--r-- | 17.1 KB |
scsi_ioctl.c | -rw-r--r-- | 19.1 KB |
sed-opal.c | -rw-r--r-- | 58.8 KB |
t10-pi.c | -rw-r--r-- | 7.9 KB |
Computing file changes ...