From: Steve French <smfrench@gmail.com>
To: Shuhao Fu <sfual@cse.ust.hk>
Cc: Steve French <sfrench@samba.org>,
Paulo Alcantara <pc@manguebit.org>,
Ronnie Sahlberg <ronniesahlberg@gmail.com>,
Shyam Prasad N <sprasad@microsoft.com>,
Tom Talpey <tom@talpey.com>,
Bharath SM <bharathsm@microsoft.com>,
linux-cifs@vger.kernel.org, samba-technical@lists.samba.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] smb: client: fix refcount leak in smb2_set_path_attr
Date: Tue, 4 Nov 2025 10:12:13 -0600 [thread overview]
Message-ID: <CAH2r5mu7s4p88RhUbCm5mqUvEVM60OOTTJOZ+rz09nFfc+t3mQ@mail.gmail.com> (raw)
In-Reply-To: <aQoYCxKqMHwH4sOK@osx.local>
There are multiple callers - are there callers that don't call
"set_writeable_path()" ? And so could cause the reverse refcount
issue?
On Tue, Nov 4, 2025 at 9:21 AM Shuhao Fu <sfual@cse.ust.hk> wrote:
>
> Fix refcount leak in `smb2_set_path_attr` when path conversion fails.
>
> Function `cifs_get_writable_path` returns `cfile` with its reference
> counter `cfile->count` increased on success. Function `smb2_compound_op`
> would decrease the reference counter for `cfile`, as stated in its
> comment. By calling `smb2_rename_path`, the reference counter of `cfile`
> would leak if `cifs_convert_path_to_utf16` fails in `smb2_set_path_attr`.
>
> Fixes: 8de9e86c67ba ("cifs: create a helper to find a writeable handle by path name")
> Signed-off-by: Shuhao Fu <sfual@cse.ust.hk>
> ---
> fs/smb/client/smb2inode.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/fs/smb/client/smb2inode.c b/fs/smb/client/smb2inode.c
> index 09e3fc81d..69cb81fa0 100644
> --- a/fs/smb/client/smb2inode.c
> +++ b/fs/smb/client/smb2inode.c
> @@ -1294,6 +1294,8 @@ static int smb2_set_path_attr(const unsigned int xid, struct cifs_tcon *tcon,
> smb2_to_name = cifs_convert_path_to_utf16(to_name, cifs_sb);
> if (smb2_to_name == NULL) {
> rc = -ENOMEM;
> + if (cfile)
> + cifsFileInfo_put(cfile);
> goto smb2_rename_path;
> }
> in_iov.iov_base = smb2_to_name;
> --
> 2.39.5 (Apple Git-154)
>
>
--
Thanks,
Steve
next prev parent reply other threads:[~2025-11-04 16:12 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-04 15:13 [PATCH] smb: client: fix refcount leak in smb2_set_path_attr Shuhao Fu
2025-11-04 16:12 ` Steve French [this message]
2025-11-04 16:23 ` Henrique Carvalho
2025-11-04 16:56 ` Shuhao Fu
2025-11-04 18:34 ` Henrique Carvalho
2025-11-04 16:54 ` Shuhao Fu
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