linux-kernel - Re: [PATCH] netfs: Delete subtree of 'fs/netfs' when netfs module exits

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <952423.1724841455@warthog.procyon.org.uk>
Date: Wed, 28 Aug 2024 11:37:35 +0100
From: David Howells <dhowells@...hat.com>
To: libaokun@...weicloud.com
Cc: dhowells@...hat.com, netfs@...ts.linux.dev, jlayton@...nel.org,
    hsiangkao@...ux.alibaba.com, jefflexu@...ux.alibaba.com,
    linux-erofs@...ts.ozlabs.org, brauner@...nel.org,
    linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
    yangerkun@...wei.com, houtao1@...wei.com, yukuai3@...wei.com,
    wozizhi@...wei.com, Baokun Li <libaokun1@...wei.com>,
    stable@...nel.org
Subject: Re: [PATCH] netfs: Delete subtree of 'fs/netfs' when netfs module exits

libaokun@...weicloud.com wrote:

> In netfs_init() or fscache_proc_init(), we create dentry under 'fs/netfs',
> but in netfs_exit(), we only delete the proc entry of 'fs/netfs' without
> deleting its subtree. This triggers the following WARNING:
> 
> ==================================================================
> remove_proc_entry: removing non-empty directory 'fs/netfs', leaking at least 'requests'
> WARNING: CPU: 4 PID: 566 at fs/proc/generic.c:717 remove_proc_entry+0x160/0x1c0
> Modules linked in: netfs(-)
> CPU: 4 UID: 0 PID: 566 Comm: rmmod Not tainted 6.11.0-rc3 #860
> RIP: 0010:remove_proc_entry+0x160/0x1c0
> Call Trace:
>  <TASK>
>  netfs_exit+0x12/0x620 [netfs]
>  __do_sys_delete_module.isra.0+0x14c/0x2e0
>  do_syscall_64+0x4b/0x110
>  entry_SYSCALL_64_after_hwframe+0x76/0x7e
> ==================================================================
> 
> Therefore use remove_proc_subtree instead() of remove_proc_entry() to
> fix the above problem.
> 
> Fixes: 7eb5b3e3a0a5 ("netfs, fscache: Move /proc/fs/fscache to /proc/fs/netfs and put in a symlink")
> Cc: stable@...nel.org
> Signed-off-by: Baokun Li <libaokun1@...wei.com>

Should remove_proc_entry() just remove the entire subtree anyway?

But you can add:

	Acked-by: David Howells <dhowells@...hat.com>

David