From: Steve French <stfrench@microsoft.com>
Date: Thu, 1 Jul 2021 20:44:27 -0500
Subject: [PATCH] CIFS: Clarify SMB1 code for UnixCreateSymLink
Git-commit: ded2d99cef169a12a1d3961a540728675f525846
References: bsc#1190317
Patch-mainline: v5.14-rc1
Coverity also complains about the way we calculate the offset
(starting from the address of a 4 byte array within the
header structure rather than from the beginning of the struct
plus 4 bytes) for creating SMB1 symlinks when using the Unix
extensions. This doesn't change the address but
makes it slightly clearer.
Addresses-Coverity: 711530 ("Out of bounds read")
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
---
fs/cifs/cifssmb.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index ea12fa6eacb6..a14d3f533301 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -2925,7 +2925,8 @@ CIFSUnixCreateSymLink(const unsigned int xid, struct cifs_tcon *tcon,
InformationLevel) - 4;
offset = param_offset + params;
- data_offset = (char *) (&pSMB->hdr.Protocol) + offset;
+ /* SMB offsets are from the beginning of SMB which is 4 bytes in, after RFC1001 field */
+ data_offset = (char *)pSMB + offset + 4;
if (pSMB->hdr.Flags2 & SMBFLG2_UNICODE) {
name_len_target =
cifsConvertToUTF16((__le16 *) data_offset, toName,
--
2.33.0