From: Tony Battersby <[email protected]>
To: Jens Axboe <[email protected]>,
Olivier Langlois <[email protected]>,
"Eric W. Biederman" <[email protected]>,
Oleg Nesterov <[email protected]>
Cc: Linus Torvalds <[email protected]>,
Linux Kernel Mailing List <[email protected]>,
linux-fsdevel <[email protected]>,
io-uring <[email protected]>,
Alexander Viro <[email protected]>,
"Pavel Begunkov>" <[email protected]>
Subject: Re: [PATCH] coredump: Limit what can interrupt coredumps
Date: Tue, 17 Aug 2021 17:39:18 -0400 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On 8/17/21 5:28 PM, Jens Axboe wrote:
>
> Another approach - don't allow TWA_SIGNAL task_work to get queued if
> PF_SIGNALED has been set on the task. This is similar to how we reject
> task_work_add() on process exit, and the callers must be able to handle
> that already.
>
> Can you test this one on top of your 5.10-stable?
>
>
> diff --git a/fs/coredump.c b/fs/coredump.c
> index 07afb5ddb1c4..ca7c1ee44ada 100644
> --- a/fs/coredump.c
> +++ b/fs/coredump.c
> @@ -602,6 +602,14 @@ void do_coredump(const kernel_siginfo_t *siginfo)
> .mm_flags = mm->flags,
> };
>
> + /*
> + * task_work_add() will refuse to add work after PF_SIGNALED has
> + * been set, ensure that we flush any pending TIF_NOTIFY_SIGNAL work
> + * if any was queued before that.
> + */
> + if (test_thread_flag(TIF_NOTIFY_SIGNAL))
> + tracehook_notify_signal();
> +
> audit_core_dumps(siginfo->si_signo);
>
> binfmt = mm->binfmt;
> diff --git a/kernel/task_work.c b/kernel/task_work.c
> index 1698fbe6f0e1..1ab28904adc4 100644
> --- a/kernel/task_work.c
> +++ b/kernel/task_work.c
> @@ -41,6 +41,12 @@ int task_work_add(struct task_struct *task, struct callback_head *work,
> head = READ_ONCE(task->task_works);
> if (unlikely(head == &work_exited))
> return -ESRCH;
> + /*
> + * TIF_NOTIFY_SIGNAL notifications will interfere with
> + * a core dump in progress, reject them.
> + */
> + if ((task->flags & PF_SIGNALED) && notify == TWA_SIGNAL)
> + return -ESRCH;
> work->next = head;
> } while (cmpxchg(&task->task_works, head, work) != head);
>
>
Doesn't compile. 5.10 doesn't have TIF_NOTIFY_SIGNAL.
Tony Battersby
next prev parent reply other threads:[~2021-08-17 21:39 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <[email protected]>
[not found] ` <[email protected]>
[not found] ` <87h7i694ij.fsf_-_@disp2133>
2021-06-09 20:33 ` [RFC] coredump: Do not interrupt dump for TIF_NOTIFY_SIGNAL Linus Torvalds
2021-06-09 20:48 ` Eric W. Biederman
2021-06-09 20:52 ` Linus Torvalds
2021-06-09 21:02 ` Olivier Langlois
2021-06-09 21:05 ` Eric W. Biederman
2021-06-09 21:26 ` Olivier Langlois
2021-06-09 21:56 ` Olivier Langlois
2021-06-10 14:26 ` Eric W. Biederman
2021-06-10 15:17 ` Olivier Langlois
2021-06-10 18:58 ` [CFT}[PATCH] coredump: Limit what can interrupt coredumps Eric W. Biederman
2021-06-10 19:10 ` Linus Torvalds
2021-06-10 19:18 ` Eric W. Biederman
2021-06-10 19:50 ` Linus Torvalds
2021-06-10 20:11 ` [PATCH] " Eric W. Biederman
2021-06-10 21:04 ` Linus Torvalds
2021-06-12 14:36 ` Olivier Langlois
2021-06-12 16:26 ` Jens Axboe
2021-06-14 14:10 ` Oleg Nesterov
2021-06-14 16:37 ` Eric W. Biederman
2021-06-14 16:59 ` Oleg Nesterov
2021-06-15 22:08 ` Eric W. Biederman
2021-06-16 19:23 ` Olivier Langlois
2021-06-16 20:00 ` Eric W. Biederman
2021-06-18 20:05 ` Olivier Langlois
2021-08-05 13:06 ` Olivier Langlois
2021-08-10 21:48 ` Tony Battersby
2021-08-11 20:47 ` Olivier Langlois
2021-08-12 1:55 ` Jens Axboe
2021-08-12 13:53 ` Tony Battersby
2021-08-15 20:42 ` Olivier Langlois
2021-08-16 13:02 ` Pavel Begunkov
2021-08-16 13:06 ` Pavel Begunkov
2021-08-17 18:15 ` Jens Axboe
2021-08-17 18:24 ` Jens Axboe
2021-08-17 19:29 ` Tony Battersby
2021-08-17 19:59 ` Jens Axboe
2021-08-17 21:28 ` Jens Axboe
2021-08-17 21:39 ` Tony Battersby [this message]
2021-08-17 22:05 ` Jens Axboe
2021-08-18 14:37 ` Tony Battersby
2021-08-18 14:46 ` Jens Axboe
2021-08-18 2:57 ` Jens Axboe
2021-08-18 2:58 ` Jens Axboe
2021-08-21 10:08 ` Olivier Langlois
2021-08-21 16:47 ` Olivier Langlois
2021-08-21 16:51 ` Jens Axboe
2021-08-21 17:21 ` Olivier Langlois
2021-08-21 9:52 ` Olivier Langlois
2021-08-21 9:48 ` Olivier Langlois
2021-10-22 14:13 ` [RFC] coredump: Do not interrupt dump for TIF_NOTIFY_SIGNAL Pavel Begunkov
2021-12-24 1:34 ` Olivier Langlois
2021-12-24 10:37 ` Pavel Begunkov
2021-12-24 19:52 ` Eric W. Biederman
2021-12-28 11:24 ` Pavel Begunkov
2022-03-14 23:58 ` Eric W. Biederman
[not found] ` <[email protected]>
2022-06-01 3:15 ` Jens Axboe
2022-07-20 16:49 ` [PATCH 0/2] coredump: Allow io_uring using apps to dump to pipes Eric W. Biederman
2022-07-20 16:50 ` [PATCH 1/2] signal: Move stopping for the coredump from do_exit into get_signal Eric W. Biederman
2022-07-20 16:51 ` [PATCH 2/2] coredump: Allow coredumps to pipes to work with io_uring Eric W. Biederman
2022-08-22 21:16 ` Olivier Langlois
2022-08-23 3:35 ` Olivier Langlois
2022-08-23 18:22 ` Eric W. Biederman
2022-08-23 18:27 ` Jens Axboe
2022-08-24 15:11 ` Eric W. Biederman
2022-08-24 15:51 ` Jens Axboe
2022-01-05 19:39 ` [RFC] coredump: Do not interrupt dump for TIF_NOTIFY_SIGNAL Olivier Langlois
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