From: Henrique Carvalho <henrique.carvalho@suse.com>
To: Steve French <smfrench@gmail.com>, Shuhao Fu <sfual@cse.ust.hk>
Cc: Tom Talpey <tom@talpey.com>,
Shyam Prasad N <sprasad@microsoft.com>,
Paulo Alcantara <pc@manguebit.org>,
linux-cifs@vger.kernel.org, samba-technical@lists.samba.org,
linux-kernel@vger.kernel.org, Steve French <sfrench@samba.org>,
Bharath SM <bharathsm@microsoft.com>
Subject: Re: [PATCH] smb: client: fix refcount leak in smb2_set_path_attr
Date: Tue, 4 Nov 2025 13:23:33 -0300 [thread overview]
Message-ID: <648b7b14-d285-449a-a1b3-4cd062a55b02@suse.com> (raw)
In-Reply-To: <CAH2r5mu7s4p88RhUbCm5mqUvEVM60OOTTJOZ+rz09nFfc+t3mQ@mail.gmail.com>
On 11/4/25 1:12 PM, Steve French via samba-technical wrote:
> There are multiple callers - are there callers that don't call
> "set_writeable_path()" ? And so could cause the reverse refcount
> issue?
Yes... Even if it does not cause an issue today, that fix looks like it
belongs inside smb2_rename_path?
>
> 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)
>>
>>
>
>
--
Henrique
SUSE Labs
next prev parent reply other threads:[~2025-11-04 16:25 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
2025-11-04 16:23 ` Henrique Carvalho [this message]
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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