From: Thomas Gleixner <tglx@kernel.org>
To: Andrii Nakryiko <andrii@kernel.org>,
akpm@linux-foundation.org, linux-mm@kvack.org
Cc: linux-fsdevel@vger.kernel.org, bpf@vger.kernel.org,
surenb@google.com, shakeel.butt@linux.dev,
Andrii Nakryiko <andrii@kernel.org>, Ruikai Peng <ruikai@pwno.io>,
syzbot+237b5b985b78c1da9600@syzkaller.appspotmail.com
Subject: Re: [PATCH mm-hotfixes-stable] procfs: fix possible double mmput() in do_procmap_query()
Date: Tue, 10 Feb 2026 22:07:15 +0100 [thread overview]
Message-ID: <87fr789ukc.ffs@tglx> (raw)
In-Reply-To: <20260210192738.3041609-1-andrii@kernel.org>
On Tue, Feb 10 2026 at 11:27, Andrii Nakryiko wrote:
> When user provides incorrectly sized buffer for build ID for PROCMAP_QUERY we
> return with -ENAMETOOLONG error. After recent changes this condition happens
> later, after we unlocked mmap_lock/per-VMA lock and did mmput(), so original
> goto out is now wrong and will double-mmput() mm_struct. Fix by jumping
> further to clean up only vm_file and name_buf.
>
> Fixes: b5cbacd7f86f ("procfs: avoid fetching build ID while holding VMA lock")
> Reported-by: Ruikai Peng <ruikai@pwno.io>
> Reported-by: Thomas Gleixner <tglx@kernel.org>
> Reported-by: syzbot+237b5b985b78c1da9600@syzkaller.appspotmail.com
> Signed-off-by: Andrii Nakryiko <andrii@kernel.fs>
Tested-by: Thomas Gleixner <tglx@kernel.org>
I did not test this one, but the identical fix I did myself :)
next prev parent reply other threads:[~2026-02-10 21:07 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-10 19:27 Andrii Nakryiko
2026-02-10 21:07 ` Thomas Gleixner [this message]
2026-02-10 21:30 ` Shakeel Butt
2026-02-10 21:38 ` Andrii Nakryiko
2026-02-13 23:45 ` patchwork-bot+netdevbpf
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