From: Tetsuo Handa <penguin-ker...@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-bed2dd18b...@i-love.sakura.ne.jp Signed-off-by: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp> Reported-by: syzbot <syzbot+8ab2d0f39fb79fe6c...@syzkaller.appspotmail.com> Cc: Eric Biederman <ebied...@xmission.com> Reviewed-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gre...@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;
