From: Paulo Alcantara <pc@manguebit.com>
Date: Mon, 19 Jun 2023 19:52:01 +0000 (-0300)
Subject: smb: client: fix warning in cifs_match_super()
X-Git-Tag: v6.5-rc1~103^2~17
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=fc1bd51d110e206da5bee07e889d285c267a6874;p=thirdparty%2Fkernel%2Flinux.git

smb: client: fix warning in cifs_match_super()

Fix potential dereference of ERR_PTR @tlink as reported by kernel test
robot

  fs/smb/client/connect.c:2775 cifs_match_super() error: 'tlink'
  dereferencing possible ERR_PTR()

Link: https://lore.kernel.org/all/202306170124.CtQqzf0I-lkp@intel.com/
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
---

diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index 9d16626e7a669..f9e0b59802d56 100644
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -2767,8 +2767,9 @@ cifs_match_super(struct super_block *sb, void *data)
 	}
 
 	tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
-	if (tlink == NULL) {
-		/* can not match superblock if tlink were ever null */
+	if (IS_ERR_OR_NULL(tlink)) {
+		pr_warn_once("%s: skip super matching due to bad tlink(%p)\n",
+			     __func__, tlink);
 		spin_unlock(&cifs_tcp_ses_lock);
 		return 0;
 	}