From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: Axel Rasmussen <axelrasmussen@google.com>
Cc: syzbot+16b6ab88e66b34d09014@syzkaller.appspotmail.com,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
linux-mm <linux-mm@kvack.org>,
Andrew Morton <akpm@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
nsaenz@amazon.com
Subject: Re: [syzbot] [mm?] possible deadlock in __mmap_lock_do_trace_released
Date: Thu, 4 Jul 2024 22:21:50 +0900 [thread overview]
Message-ID: <e0c7a2f8-9147-42bd-b531-f51c4d0c5082@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <CAJHvVcjOjOTyrf4K+pTQ30doOx7hqheTExZY6_U+PCcdLigg7g@mail.gmail.com>
On 2024/07/03 7:35, Axel Rasmussen wrote:
> But, note that stack_map_get_build_id calls mmap_read_trylock, so I
> would expect in the recursive case that call will simply fail, and
> then stack_map_get_build_id_offset appears to deal gracefully with
> that?
Unless that mmap was already held for write (or someone has started waiting
to hold it for write), recursive mmap_read_trylock() will succeed. Thus,
unless there is a guarantee of no infinite recursion, we should implement
a safeguard based on the worst scenario.
next prev parent reply other threads:[~2024-07-04 13:22 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-02 18:54 syzbot
2024-07-02 22:08 ` Tetsuo Handa
[not found] ` <CAJHvVcjOjOTyrf4K+pTQ30doOx7hqheTExZY6_U+PCcdLigg7g@mail.gmail.com>
2024-07-04 13:21 ` Tetsuo Handa [this message]
2024-07-04 20:12 ` Jesper Dangaard Brouer
2024-07-11 14:33 ` Steven Rostedt
2024-08-19 4:40 ` syzbot
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