Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.2 134/137] kexec: bail out upon SIGKILL when allocating memory. | Date | Sun, 6 Oct 2019 19:21:58 +0200 |
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From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
commit 7c3a6aedcd6aae0a32a527e68669f7dd667492d1 upstream.
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- kernel/kexec_core.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -300,6 +300,8 @@ static struct page *kimage_alloc_pages(g { struct page *pages; + if (fatal_signal_pending(current)) + return NULL; pages = alloc_pages(gfp_mask & ~__GFP_ZERO, order); if (pages) { unsigned int count, i;
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