From: Eric Biggers <ebiggers@kernel.org>
To: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Eric Biederman <ebiederm@xmission.com>,
syzbot <syzbot+8ab2d0f39fb79fe6ca40@syzkaller.appspotmail.com>,
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: Re: [PATCH] kexec: Bail out upon SIGKILL when allocating memory.
Date: Tue, 23 Jul 2019 19:54:22 -0700 [thread overview]
Message-ID: <20190724025422.GQ643@sol.localdomain> (raw)
In-Reply-To: <993c9185-d324-2640-d061-bed2dd18b1f7@I-love.SAKURA.ne.jp>
On Fri, Jun 14, 2019 at 07:16:18PM +0900, Tetsuo Handa wrote:
> 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
>
> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Reported-by: syzbot <syzbot+8ab2d0f39fb79fe6ca40@syzkaller.appspotmail.com>
> ---
> kernel/kexec_core.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
> index fd5c95f..2b25d95 100644
> --- a/kernel/kexec_core.c
> +++ b/kernel/kexec_core.c
> @@ -302,6 +302,8 @@ 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;
> --
> 1.8.3.1
>
> --
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What happened to this patch? This bug is still occurring.
- Eric
next prev parent reply other threads:[~2019-07-24 2:54 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-12 20:53 INFO: task syz-executor can't die for more than 143 seconds syzbot
2019-06-13 2:53 ` syzbot
2019-06-14 10:16 ` [PATCH] kexec: Bail out upon SIGKILL when allocating memory Tetsuo Handa
2019-07-01 10:52 ` Tetsuo Handa
2019-07-24 2:54 ` Eric Biggers [this message]
2019-07-24 3:09 ` Tetsuo Handa
2019-06-21 9:58 ` INFO: task syz-executor can't die for more than 143 seconds Tetsuo Handa
2019-07-01 10:55 ` [PATCH] staging: android: ion: Bail out upon SIGKILL when allocating memory Tetsuo Handa
2019-07-01 11:36 ` Laura Abbott
2019-07-01 14:02 ` Sumit Semwal
2019-07-01 21:02 ` Tetsuo Handa
2019-07-01 21:21 ` Laura Abbott
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