[PATCH 5.15 497/570] smb: client: Fix refcount leak for cifs_sb_tlink

Greg Kroah-Hartman
2026-04-13T16:39:27Z

From: Shuhao Fu <sfual@cse.ust.hk>

[ Upstream commit c2b77f42205ef485a647f62082c442c1cd69d3fc ]

Fix three refcount inconsistency issues related to `cifs_sb_tlink`.

Comments for `cifs_sb_tlink` state that `cifs_put_tlink()` needs to be
called after successful calls to `cifs_sb_tlink()`. Three calls fail to
update refcount accordingly, leading to possible resource leaks.

Fixes: 8ceb98437946 ("CIFS: Move rename to ops struct")
Fixes: 2f1afe25997f ("cifs: Use smb 2 - 3 and cifsacl mount options getacl functions")
Fixes: 366ed846df60 ("cifs: Use smb 2 - 3 and cifsacl mount options setacl function")
Cc: stable@vger.kernel.org
Signed-off-by: Shuhao Fu <sfual@cse.ust.hk>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Johnny Hao <johnny_haocn@sina.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/cifs/inode.c | 6 ++++--
fs/cifs/smb2ops.c | 8 ++++----
2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 30a9a89c141bb..bb0b172c5a74d 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -2023,8 +2023,10 @@ cifs_do_rename(const unsigned int xid, struct dentry *from_dentry,
tcon = tlink_tcon(tlink);
server = tcon->ses->server;

- if (!server->ops->rename)
- return -ENOSYS;
+ if (!server->ops->rename) {
+ rc = -ENOSYS;
+ goto do_rename_exit;
+ }

/* try path-based rename first */
rc = server->ops->rename(xid, tcon, from_path, to_path, cifs_sb);
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 619905fc694e4..0a62720590daf 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3437,8 +3437,7 @@ get_smb2_acl_by_path(struct cifs_sb_info *cifs_sb,
utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
if (!utf16_path) {
rc = -ENOMEM;
- free_xid(xid);
- return ERR_PTR(rc);
+ goto put_tlink;
}

oparms.tcon = tcon;
@@ -3466,6 +3465,7 @@ get_smb2_acl_by_path(struct cifs_sb_info *cifs_sb,
SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
}

+put_tlink:
cifs_put_tlink(tlink);
free_xid(xid);

@@ -3506,8 +3506,7 @@ set_smb2_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
if (!utf16_path) {
rc = -ENOMEM;
- free_xid(xid);
- return rc;
+ goto put_tlink;
}

oparms.tcon = tcon;
@@ -3527,6 +3526,7 @@ set_smb2_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
}

+put_tlink:
cifs_put_tlink(tlink);
free_xid(xid);
return rc;
--
2.53.0