The patch titled
Subject: kexec: bail out upon SIGKILL when allocating memory.
has been added to the -mm tree. Its filename is
kexec-bail-out-upon-sigkill-when-allocating-memory.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/kexec-bail-out-upon-sigkill-when-allocating-memory.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/kexec-bail-out-upon-sigkill-when-allocating-memory.patch
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------------------------------------------------------
From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Subject: 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@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Reported-by: syzbot <syzbot+8ab2d0f39fb79fe6ca40@xxxxxxxxxxxxxxxxxxxxxxxxx>
Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/kexec_core.c | 2 ++
1 file changed, 2 insertions(+)
--- a/kernel/kexec_core.c~kexec-bail-out-upon-sigkill-when-allocating-memory
+++ a/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;
_
Patches currently in -mm which might be from penguin-kernel@xxxxxxxxxxxxxxxxxxx are
info-task-hung-in-generic_file_write_iter.patch
info-task-hung-in-generic_file_write-fix.patch
kexec-bail-out-upon-sigkill-when-allocating-memory.patch
