From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A321E2F6577; Fri, 21 Nov 2025 13:22:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763731347; cv=none; b=L7IpwQnpwES+GBOwgS8U/VzzxB2GuQNWvrJszmOz7+5Qmjioeij8Q6HaMyNT7RQ12cj3yaoSZqWbD/Pq4GYz57O/uoDKgnVGWR1HzXo0//Pz4K7/j/EZ6jbyyiMfQnLY9aJ4LfhstyeBT0avKQYvIWzsjH18gvSVV3iSm2ycFC0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763731347; c=relaxed/simple; bh=Z1ClbecyOEX99EHbIxOXMsHW0jkl4wdk5Rj6Hk0Cy64=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hI1FqO1hRu4L56W7QeO613HTriA+zmoeYxYX3w/lhhf/7BQjRYoKefrBPCwtSEJAeX1nMc3cO4XLgkZCHIi29KfWhPiaBZNuPbKK5CFM2aV5OJ/sF60E9SQSWLWqYi+bW6kX6AddgfWHSA0wf1ipRNtoR/tcE53j4z750r92OoU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=k+r5N/FO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="k+r5N/FO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28CFEC4CEF1; Fri, 21 Nov 2025 13:22:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1763731347; bh=Z1ClbecyOEX99EHbIxOXMsHW0jkl4wdk5Rj6Hk0Cy64=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k+r5N/FO3p0WqXQpOMg/mYV7CjqVzLjL6o1Zh0fAy0gcdSma6mYZOlxT2Qwob7JDB RzQyec1a0TJoFY6A1+wZXCklfc+tFW9+felg+7srIOsmixhxf2qr1+yJw2wYse5PYi Sz5DqXUB4s7JclMTIslrYkJDESfyE5JXmSwYheJs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ryusuke Konishi , syzbot+24d8b70f039151f65590@syzkaller.appspotmail.com, Edward Adam Davis , Andrew Morton Subject: [PATCH 6.17 176/247] nilfs2: avoid having an active sc_timer before freeing sci Date: Fri, 21 Nov 2025 14:12:03 +0100 Message-ID: <20251121130201.036491661@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251121130154.587656062@linuxfoundation.org> References: <20251121130154.587656062@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Edward Adam Davis commit 9a6b60cb147d53968753a34805211d2e5e08c027 upstream. Because kthread_stop did not stop sc_task properly and returned -EINTR, the sc_timer was not properly closed, ultimately causing the problem [1] reported by syzbot when freeing sci due to the sc_timer not being closed. Because the thread sc_task main function nilfs_segctor_thread() returns 0 when it succeeds, when the return value of kthread_stop() is not 0 in nilfs_segctor_destroy(), we believe that it has not properly closed sc_timer. We use timer_shutdown_sync() to sync wait for sc_timer to shutdown, and set the value of sc_task to NULL under the protection of lock sc_state_lock, so as to avoid the issue caused by sc_timer not being properly shutdowned. [1] ODEBUG: free active (active state 0) object: 00000000dacb411a object type: timer_list hint: nilfs_construction_timeout Call trace: nilfs_segctor_destroy fs/nilfs2/segment.c:2811 [inline] nilfs_detach_log_writer+0x668/0x8cc fs/nilfs2/segment.c:2877 nilfs_put_super+0x4c/0x12c fs/nilfs2/super.c:509 Link: https://lkml.kernel.org/r/20251029225226.16044-1-konishi.ryusuke@gmail.com Fixes: 3f66cc261ccb ("nilfs2: use kthread_create and kthread_stop for the log writer thread") Signed-off-by: Ryusuke Konishi Reported-by: syzbot+24d8b70f039151f65590@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=24d8b70f039151f65590 Tested-by: syzbot+24d8b70f039151f65590@syzkaller.appspotmail.com Signed-off-by: Edward Adam Davis Cc: [6.12+] Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- fs/nilfs2/segment.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -2768,7 +2768,12 @@ static void nilfs_segctor_destroy(struct if (sci->sc_task) { wake_up(&sci->sc_wait_daemon); - kthread_stop(sci->sc_task); + if (kthread_stop(sci->sc_task)) { + spin_lock(&sci->sc_state_lock); + sci->sc_task = NULL; + timer_shutdown_sync(&sci->sc_timer); + spin_unlock(&sci->sc_state_lock); + } } spin_lock(&sci->sc_state_lock);