From: Shuhao Fu <sfual@cse.ust.hk>
Date: Thu, 16 Oct 2025 02:52:55 +0000 (+0000)
Subject: smb: client: Fix refcount leak for cifs_sb_tlink
X-Git-Tag: v6.12.55~132
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e15605b68b490186da2ad8029c0351a9cfb0b9af;p=thirdparty%2Fkernel%2Fstable.git

smb: client: Fix refcount leak for cifs_sb_tlink

commit c2b77f42205ef485a647f62082c442c1cd69d3fc upstream.

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/smb/client/inode.c b/fs/smb/client/inode.c
index e06d02b68c538..4862a9518a321 100644
--- a/fs/smb/client/inode.c
+++ b/fs/smb/client/inode.c
@@ -2381,8 +2381,10 @@ 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_dentry,
diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index 1b30035d02bc5..35299967737f1 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -3134,8 +3134,7 @@ 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 = (struct cifs_open_parms) {
@@ -3167,6 +3166,7 @@ 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);
 
@@ -3207,8 +3207,7 @@ set_smb2_acl(struct smb_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 = (struct cifs_open_parms) {
@@ -3229,6 +3228,7 @@ set_smb2_acl(struct smb_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;