From: Pavel Begunkov <[email protected]>
To: Joseph Qi <[email protected]>,
Xiaoguang Wang <[email protected]>,
[email protected]
Cc: [email protected]
Subject: Re: [PATCH] io_uring: always let io_iopoll_complete() complete polled io.
Date: Fri, 4 Dec 2020 20:31:43 +0000 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On 03/12/2020 02:30, Joseph Qi wrote:
> This patch can also fix another BUG I'm looking at:
>
> [ 61.359713] BUG: KASAN: double-free or invalid-free in io_dismantle_req+0x938/0xf40
> ...
> [ 61.409315] refcount_t: underflow; use-after-free.
> [ 61.410261] WARNING: CPU: 1 PID: 1022 at lib/refcount.c:28 refcount_warn_saturate+0x266/0x2a0
> ...
>
> It blames io_put_identity() has been called more than once and then
> identity->count is underflow.
Joseph, regarding your double-free
1. did you figure out how exactly this happens?
2. is it appears consistently so you can be sure that it's fixed
3. do you have a reproducer?
4. can you paste a full log of this BUG? (not cutting the stacktrace)
There are problems left even with this patch applied, but I need to
confirm which bug you saw.
--
Pavel Begunkov
next prev parent reply other threads:[~2020-12-04 20:35 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-02 11:31 [PATCH] io_uring: always let io_iopoll_complete() complete polled io Xiaoguang Wang
2020-12-02 17:00 ` Pavel Begunkov
2020-12-02 17:09 ` Pavel Begunkov
2020-12-03 2:30 ` Joseph Qi
2020-12-04 20:31 ` Pavel Begunkov [this message]
[not found] ` <[email protected]>
2020-12-05 16:16 ` Pavel Begunkov
2020-12-06 22:25 ` Pavel Begunkov
2020-12-11 12:29 ` Pavel Begunkov
2020-12-11 14:59 ` Xiaoguang Wang
2020-12-11 18:20 ` Pavel Begunkov
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