[CIFS] Fix buffer overflow if server sends corrupt response to small
request
In SendReceive() function in transport.c - it memcpy's
message payload into a buffer passed via out_buf param. The function
assumes that all buffers are of size (CIFSMaxBufSize +
MAX_CIFS_HDR_SIZE) , unfortunately it is also called with smaller
(MAX_CIFS_SMALL_BUFFER_SIZE) buffers. There are eight callers
(SMB worker functions) which are primarily affected by this change:
TreeDisconnect, uLogoff, Close, findClose, SetFileSize, SetFileTimes,
Lock and PosixLock
CC: Dave Kleikamp <shaggy@austin.ibm.com>
CC: Przemyslaw Wegrzyn <czajnik@czajsoft.pl>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index c52a76f..26e1087 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2374,7 +2374,7 @@
pSMB->req_no_secext.ByteCount = cpu_to_le16(count);
rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response,
- &bytes_returned, 1);
+ &bytes_returned, CIFS_LONG_OP);
if (rc) {
/* rc = map_smb_to_linux_error(smb_buffer_response); now done in SendReceive */
} else if ((smb_buffer_response->WordCount == 3)
@@ -2678,7 +2678,7 @@
pSMB->req.ByteCount = cpu_to_le16(count);
rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response,
- &bytes_returned, 1);
+ &bytes_returned, CIFS_LONG_OP);
if (smb_buffer_response->Status.CifsError ==
cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))
@@ -3105,7 +3105,7 @@
pSMB->req.ByteCount = cpu_to_le16(count);
rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response,
- &bytes_returned, 1);
+ &bytes_returned, CIFS_LONG_OP);
if (rc) {
/* rc = map_smb_to_linux_error(smb_buffer_response) done in SendReceive now */
} else if ((smb_buffer_response->WordCount == 3) ||
@@ -3381,7 +3381,8 @@
pSMB->hdr.smb_buf_length += count;
pSMB->ByteCount = cpu_to_le16(count);
- rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length, 0);
+ rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
+ CIFS_STD_OP);
/* if (rc) rc = map_smb_to_linux_error(smb_buffer_response); */
/* above now done in SendReceive */