From: Paulo Alcantara <pc@cjr.nz>
Date: Thu, 6 Oct 2022 13:04:05 -0300
Subject: [PATCH] cifs: prevent copying past input buffer boundaries
Git-commit: 9ee2afe5207b63b20426ee081f486d831bae871d
References: bsc#1193629
Patch-mainline: v6.1-rc1

Prevent copying past @data buffer in smb2_validate_and_copy_iov() as
the output buffer in @iov might be potentially bigger and thus copying
more bytes than requested in @minbufsize.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Paulo Alcantara <palcantara@suse.de>
---
 fs/cifs/smb2pdu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index b3c4d2e54eaa..a3b77df2848c 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -3485,7 +3485,7 @@ smb2_validate_and_copy_iov(unsigned int offset, unsigned int buffer_length,
 	if (rc)
 		return rc;
 
-	memcpy(data, begin_of_buf, buffer_length);
+	memcpy(data, begin_of_buf, minbufsize);
 
 	return 0;
 }
@@ -3609,7 +3609,7 @@ query_info(const unsigned int xid, struct cifs_tcon *tcon,
 
 	rc = smb2_validate_and_copy_iov(le16_to_cpu(rsp->OutputBufferOffset),
 					le32_to_cpu(rsp->OutputBufferLength),
-					&rsp_iov, min_len, *data);
+					&rsp_iov, dlen ? *dlen : min_len, *data);
 	if (rc && allocated) {
 		kfree(*data);
 		*data = NULL;
-- 
2.38.0