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| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2019-09-25 16:47:33 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-25 17:51:40 -0700 |
| commit | 7c3a6aedcd6aae0a32a527e68669f7dd667492d1 (patch) | |
| tree | c25300fde2ccb706b7b96eac01545556aa59da66 /kernel/kexec_core.c | |
| parent | 2a4a4082cd4438333b5ecffdd15d1a484e5a83c7 (diff) | |
| download | lwn-7c3a6aedcd6aae0a32a527e68669f7dd667492d1.tar.gz lwn-7c3a6aedcd6aae0a32a527e68669f7dd667492d1.zip | |
kexec: bail out upon SIGKILL when allocating memory.
syzbot found that a thread can stall for minutes inside kexec_load() after
that thread was killed by SIGKILL [1]. It turned out that the reproducer
was trying to allocate 2408MB of memory using kimage_alloc_page() from
kimage_load_normal_segment(). Let's check for SIGKILL before doing memory
allocation.
[1] https://syzkaller.appspot.com/bug?id=a0e3436829698d5824231251fad9d8e998f94f5e
Link: http://lkml.kernel.org/r/993c9185-d324-2640-d061-bed2dd18b1f7@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+8ab2d0f39fb79fe6ca40@syzkaller.appspotmail.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/kexec_core.c')
| -rw-r--r-- | kernel/kexec_core.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index d5870723b8ad..15d70a90b50d 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -300,6 +300,8 @@ static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order) { struct page *pages; + if (fatal_signal_pending(current)) + return NULL; pages = alloc_pages(gfp_mask & ~__GFP_ZERO, order); if (pages) { unsigned int count, i; |