From: Steve French <stfrench@microsoft.com>
Date: Wed, 7 Jul 2021 13:34:47 -0500
Subject: [PATCH] CIFS: Clarify SMB1 code for rename open file
Git-commit: f371793d6e13a1387b83a72d7bb2c0e3a9ea654f
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 SMB1 RenameOpenFile. This changeset
doesn't change the address but makes it slightly clearer.
Addresses-Coverity: 711521 ("Out of bounds write")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
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 0863238ddd20..16bd4cf3bceb 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -2767,7 +2767,8 @@ int CIFSSMBRenameOpenFile(const unsigned int xid, struct cifs_tcon *pTcon,
param_offset = offsetof(struct smb_com_transaction2_sfi_req, Fid) - 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;
rename_info = (struct set_file_rename *) data_offset;
pSMB->MaxParameterCount = cpu_to_le16(2);
pSMB->MaxDataCount = cpu_to_le16(1000); /* BB find max SMB from sess */
--
2.33.0