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authorTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>2019-09-26 02:47:33 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-09-26 03:51:40 +0300
commit7c3a6aedcd6aae0a32a527e68669f7dd667492d1 (patch)
treec25300fde2ccb706b7b96eac01545556aa59da66 /kernel
parent2a4a4082cd4438333b5ecffdd15d1a484e5a83c7 (diff)
downloadlinux-7c3a6aedcd6aae0a32a527e68669f7dd667492d1.tar.xz
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')
-rw-r--r--kernel/kexec_core.c2
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;