From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Date: Fri, 13 Apr 2018 10:13:29 -0500
Subject: [PATCH] cifs: smb2ops: Fix NULL check in smb2_query_symlink
Git-commit: 0d568cd34eb04acf05c26f360d1a0f071f0bb636
Patch-mainline: v4.17-rc2
References: bsc#1144333
The current code null checks variable err_buf, which is always null
when it is checked, hence utf16_path is free'd and the function
returns -ENOENT everytime it is called, making it impossible for the
execution path to reach the following code:
err_buf = err_iov.iov_base;
Fix this by null checking err_iov.iov_base instead of err_buf. Also,
notice that err_buf no longer needs to be initialized to NULL.
Addresses-Coverity-ID: 1467876 ("Logically dead code")
Fixes: 2d636199e400 ("cifs: Change SMB2_open to return an iov for the error parameter")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Acked-by: Aurelien Aptel <aaptel@suse.com>
---
fs/cifs/smb2ops.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index b4ae932ea134..38ebf3f357d2 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -1452,7 +1452,7 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
struct cifs_open_parms oparms;
struct cifs_fid fid;
struct kvec err_iov = {NULL, 0};
- struct smb2_err_rsp *err_buf = NULL;
+ struct smb2_err_rsp *err_buf;
struct smb2_symlink_err_rsp *symlink;
unsigned int sub_len;
unsigned int sub_offset;
@@ -1476,7 +1476,7 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, &err_iov);
- if (!rc || !err_buf) {
+ if (!rc || !err_iov.iov_base) {
kfree(utf16_path);
return -ENOENT;
}
--
2.16.4