[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>

1 files changed, 36 insertions, 61 deletions

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 59d7b7c..9e8a6be 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -698,9 +698,7 @@ int
 CIFSSMBTDis(const int xid, struct cifsTconInfo *tcon)
 {
 	struct smb_hdr *smb_buffer;
-	struct smb_hdr *smb_buffer_response; /* BB removeme BB */
 	int rc = 0;
-	int length;
 
 	cFYI(1, ("In tree disconnect"));
 	/*
@@ -737,16 +735,12 @@ CIFSSMBTDis(const int xid, struct cifsTconInfo *tcon)
 	if (rc) {
 		up(&tcon->tconSem);
 		return rc;
-	} else {
-		smb_buffer_response = smb_buffer; /* BB removeme BB */
 	}
-	rc = SendReceive(xid, tcon->ses, smb_buffer, smb_buffer_response,
-			 &length, 0);
+
+	rc = SendReceiveNoRsp(xid, tcon->ses, smb_buffer, 0);
 	if (rc)
 		cFYI(1, ("Tree disconnect failed %d", rc));
 
-	if (smb_buffer)
-		cifs_small_buf_release(smb_buffer);
 	up(&tcon->tconSem);
 
 	/* No need to return error on this operation if tid invalidated and
@@ -760,10 +754,8 @@ CIFSSMBTDis(const int xid, struct cifsTconInfo *tcon)
 int
 CIFSSMBLogoff(const int xid, struct cifsSesInfo *ses)
 {
-	struct smb_hdr *smb_buffer_response;
 	LOGOFF_ANDX_REQ *pSMB;
 	int rc = 0;
-	int length;
 
 	cFYI(1, ("In SMBLogoff for session disconnect"));
 	if (ses)
@@ -782,8 +774,6 @@ CIFSSMBLogoff(const int xid, struct cifsSesInfo *ses)
 		return rc;
 	}
 
-	smb_buffer_response = (struct smb_hdr *)pSMB; /* BB removeme BB */
-
 	if (ses->server) {
 		pSMB->hdr.Mid = GetNextMid(ses->server);
 
@@ -795,8 +785,7 @@ CIFSSMBLogoff(const int xid, struct cifsSesInfo *ses)
 	pSMB->hdr.Uid = ses->Suid;
 
 	pSMB->AndXCommand = 0xFF;
-	rc = SendReceive(xid, ses, (struct smb_hdr *) pSMB,
-			 smb_buffer_response, &length, 0);
+	rc = SendReceiveNoRsp(xid, ses, (struct smb_hdr *) pSMB, 0);
 	if (ses->server) {
 		atomic_dec(&ses->server->socketUseCount);
 		if (atomic_read(&ses->server->socketUseCount) == 0) {
@@ -807,7 +796,6 @@ CIFSSMBLogoff(const int xid, struct cifsSesInfo *ses)
 		}
 	}
 	up(&ses->sesSem);
-	cifs_small_buf_release(pSMB);
 
 	/* if session dead then we do not need to do ulogoff,
 		since server closed smb session, no sense reporting
@@ -1255,7 +1243,7 @@ OldOpenRetry:
 	pSMB->ByteCount = cpu_to_le16(count);
 	/* long_op set to 1 to allow for oplock break timeouts */
 	rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
-			 (struct smb_hdr *) pSMBr, &bytes_returned, 1);
+			(struct smb_hdr *)pSMBr, &bytes_returned, CIFS_LONG_OP);
 	cifs_stats_inc(&tcon->num_opens);
 	if (rc) {
 		cFYI(1, ("Error in Open = %d", rc));
@@ -1368,7 +1356,7 @@ openRetry:
 	pSMB->ByteCount = cpu_to_le16(count);
 	/* long_op set to 1 to allow for oplock break timeouts */
 	rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
-			 (struct smb_hdr *) pSMBr, &bytes_returned, 1);
+			(struct smb_hdr *)pSMBr, &bytes_returned, CIFS_LONG_OP);
 	cifs_stats_inc(&tcon->num_opens);
 	if (rc) {
 		cFYI(1, ("Error in Open = %d", rc));
@@ -1446,7 +1434,7 @@ CIFSSMBRead(const int xid, struct cifsTconInfo *tcon, const int netfid,
 	iov[0].iov_base = (char *)pSMB;
 	iov[0].iov_len = pSMB->hdr.smb_buf_length + 4;
 	rc = SendReceive2(xid, tcon->ses, iov, 1 /* num iovecs */,
-			 &resp_buf_type, 0 /* not long op */, 1 /* log err */ );
+			 &resp_buf_type, CIFS_STD_OP | CIFS_LOG_ERROR);
 	cifs_stats_inc(&tcon->num_reads);
 	pSMBr = (READ_RSP *)iov[0].iov_base;
 	if (rc) {
@@ -1665,7 +1653,7 @@ CIFSSMBWrite2(const int xid, struct cifsTconInfo *tcon,
 
 
 	rc = SendReceive2(xid, tcon->ses, iov, n_vec + 1, &resp_buf_type,
-			  long_op, 0 /* do not log STATUS code */ );
+			  long_op);
 	cifs_stats_inc(&tcon->num_writes);
 	if (rc) {
 		cFYI(1, ("Send error Write2 = %d", rc));
@@ -1707,7 +1695,7 @@ CIFSSMBLock(const int xid, struct cifsTconInfo *tcon,
 	int timeout = 0;
 	__u16 count;
 
-	cFYI(1, ("In CIFSSMBLock - timeout %d numLock %d", waitFlag, numLock));
+	cFYI(1, ("CIFSSMBLock timeout %d numLock %d", waitFlag, numLock));
 	rc = small_smb_init(SMB_COM_LOCKING_ANDX, 8, tcon, (void **) &pSMB);
 
 	if (rc)
@@ -1716,10 +1704,10 @@ CIFSSMBLock(const int xid, struct cifsTconInfo *tcon,
 	pSMBr = (LOCK_RSP *)pSMB; /* BB removeme BB */
 
 	if (lockType == LOCKING_ANDX_OPLOCK_RELEASE) {
-		timeout = -1; /* no response expected */
+		timeout = CIFS_ASYNC_OP; /* no response expected */
 		pSMB->Timeout = 0;
 	} else if (waitFlag == TRUE) {
-		timeout = 3;  /* blocking operation, no timeout */
+		timeout = CIFS_BLOCKING_OP; /* blocking operation, no timeout */
 		pSMB->Timeout = cpu_to_le32(-1);/* blocking - do not time out */
 	} else {
 		pSMB->Timeout = 0;
@@ -1749,15 +1737,16 @@ CIFSSMBLock(const int xid, struct cifsTconInfo *tcon,
 	if (waitFlag) {
 		rc = SendReceiveBlockingLock(xid, tcon, (struct smb_hdr *) pSMB,
 			(struct smb_hdr *) pSMBr, &bytes_returned);
+		cifs_small_buf_release(pSMB);
 	} else {
-		rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
-			 (struct smb_hdr *) pSMBr, &bytes_returned, timeout);
+		rc = SendReceiveNoRsp(xid, tcon->ses, (struct smb_hdr *)pSMB,
+				      timeout);
+		/* SMB buffer freed by function above */
 	}
 	cifs_stats_inc(&tcon->num_locks);
 	if (rc) {
 		cFYI(1, ("Send error in Lock = %d", rc));
 	}
-	cifs_small_buf_release(pSMB);
 
 	/* Note: On -EAGAIN error only caller can retry on handle based calls
 	since file handle passed in no longer valid */
@@ -1776,7 +1765,9 @@ CIFSSMBPosixLock(const int xid, struct cifsTconInfo *tcon,
 	int rc = 0;
 	int timeout = 0;
 	int bytes_returned = 0;
+	int resp_buf_type = 0;
 	__u16 params, param_offset, offset, byte_count, count;
+	struct kvec iov[1];
 
 	cFYI(1, ("Posix Lock"));
 
@@ -1818,7 +1809,7 @@ CIFSSMBPosixLock(const int xid, struct cifsTconInfo *tcon,
 
 	parm_data->lock_type = cpu_to_le16(lock_type);
 	if (waitFlag) {
-		timeout = 3;  /* blocking operation, no timeout */
+		timeout = CIFS_BLOCKING_OP; /* blocking operation, no timeout */
 		parm_data->lock_flags = cpu_to_le16(1);
 		pSMB->Timeout = cpu_to_le32(-1);
 	} else
@@ -1838,8 +1829,13 @@ CIFSSMBPosixLock(const int xid, struct cifsTconInfo *tcon,
 		rc = SendReceiveBlockingLock(xid, tcon, (struct smb_hdr *) pSMB,
 			(struct smb_hdr *) pSMBr, &bytes_returned);
 	} else {
-		rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
-			(struct smb_hdr *) pSMBr, &bytes_returned, timeout);
+		iov[0].iov_base = (char *)pSMB;
+		iov[0].iov_len = pSMB->hdr.smb_buf_length + 4;
+		rc = SendReceive2(xid, tcon->ses, iov, 1 /* num iovecs */,
+				&resp_buf_type, timeout);
+		pSMB = NULL; /* request buf already freed by SendReceive2. Do
+				not try to free it twice below on exit */
+		pSMBr = (struct smb_com_transaction2_sfi_rsp *)iov[0].iov_base;
 	}
 
 	if (rc) {
@@ -1874,6 +1870,11 @@ plk_err_exit:
 	if (pSMB)
 		cifs_small_buf_release(pSMB);
 
+	if (resp_buf_type == CIFS_SMALL_BUFFER)
+		cifs_small_buf_release(iov[0].iov_base);
+	else if (resp_buf_type == CIFS_LARGE_BUFFER)
+		cifs_buf_release(iov[0].iov_base);
+
 	/* Note: On -EAGAIN error only caller can retry on handle based calls
 	   since file handle passed in no longer valid */
 
@@ -1886,8 +1887,6 @@ CIFSSMBClose(const int xid, struct cifsTconInfo *tcon, int smb_file_id)
 {
 	int rc = 0;
 	CLOSE_REQ *pSMB = NULL;
-	CLOSE_RSP *pSMBr = NULL;
-	int bytes_returned;
 	cFYI(1, ("In CIFSSMBClose"));
 
 /* do not retry on dead session on close */
@@ -1897,13 +1896,10 @@ CIFSSMBClose(const int xid, struct cifsTconInfo *tcon, int smb_file_id)
 	if (rc)
 		return rc;
 
-	pSMBr = (CLOSE_RSP *)pSMB; /* BB removeme BB */
-
 	pSMB->FileID = (__u16) smb_file_id;
 	pSMB->LastWriteTime = 0xFFFFFFFF;
 	pSMB->ByteCount = 0;
-	rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
-			 (struct smb_hdr *) pSMBr, &bytes_returned, 0);
+	rc = SendReceiveNoRsp(xid, tcon->ses, (struct smb_hdr *) pSMB, 0);
 	cifs_stats_inc(&tcon->num_closes);
 	if (rc) {
 		if (rc != -EINTR) {
@@ -1912,8 +1908,6 @@ CIFSSMBClose(const int xid, struct cifsTconInfo *tcon, int smb_file_id)
 		}
 	}
 
-	cifs_small_buf_release(pSMB);
-
 	/* Since session is dead, file will be closed on server already */
 	if (rc == -EAGAIN)
 		rc = 0;
@@ -3102,7 +3096,7 @@ CIFSSMBGetCIFSACL(const int xid, struct cifsTconInfo *tcon, __u16 fid,
 	iov[0].iov_len = pSMB->hdr.smb_buf_length + 4;
 
 	rc = SendReceive2(xid, tcon->ses, iov, 1 /* num iovec */, &buf_type,
-			 0 /* not long op */, 0 /* do not log STATUS codes */ );
+			 CIFS_STD_OP);
 	cifs_stats_inc(&tcon->num_acl_get);
 	if (rc) {
 		cFYI(1, ("Send error in QuerySecDesc = %d", rc));
@@ -3763,8 +3757,6 @@ CIFSFindClose(const int xid, struct cifsTconInfo *tcon,
 {
 	int rc = 0;
 	FINDCLOSE_REQ *pSMB = NULL;
-	CLOSE_RSP *pSMBr = NULL; /* BB removeme BB */
-	int bytes_returned;
 
 	cFYI(1, ("In CIFSSMBFindClose"));
 	rc = small_smb_init(SMB_COM_FIND_CLOSE2, 1, tcon, (void **)&pSMB);
@@ -3776,16 +3768,13 @@ CIFSFindClose(const int xid, struct cifsTconInfo *tcon,
 	if (rc)
 		return rc;
 
-	pSMBr = (CLOSE_RSP *)pSMB;  /* BB removeme BB */
 	pSMB->FileID = searchHandle;
 	pSMB->ByteCount = 0;
-	rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
-			 (struct smb_hdr *) pSMBr, &bytes_returned, 0);
+	rc = SendReceiveNoRsp(xid, tcon->ses, (struct smb_hdr *) pSMB, 0);
 	if (rc) {
 		cERROR(1, ("Send error in FindClose = %d", rc));
 	}
 	cifs_stats_inc(&tcon->num_fclose);
-	cifs_small_buf_release(pSMB);
 
 	/* Since session is dead, search handle closed on server already */
 	if (rc == -EAGAIN)
@@ -4707,11 +4696,9 @@ CIFSSMBSetFileSize(const int xid, struct cifsTconInfo *tcon, __u64 size,
 		   __u16 fid, __u32 pid_of_opener, int SetAllocation)
 {
 	struct smb_com_transaction2_sfi_req *pSMB  = NULL;
-	struct smb_com_transaction2_sfi_rsp *pSMBr = NULL;
 	char *data_offset;
 	struct file_end_of_file_info *parm_data;
 	int rc = 0;
-	int bytes_returned = 0;
 	__u16 params, param_offset, offset, byte_count, count;
 
 	cFYI(1, ("SetFileSize (via SetFileInfo) %lld",
@@ -4721,8 +4708,6 @@ CIFSSMBSetFileSize(const int xid, struct cifsTconInfo *tcon, __u64 size,
 	if (rc)
 		return rc;
 
-	pSMBr = (struct smb_com_transaction2_sfi_rsp *)pSMB;
-
 	pSMB->hdr.Pid = cpu_to_le16((__u16)pid_of_opener);
 	pSMB->hdr.PidHigh = cpu_to_le16((__u16)(pid_of_opener >> 16));
 
@@ -4773,17 +4758,13 @@ CIFSSMBSetFileSize(const int xid, struct cifsTconInfo *tcon, __u64 size,
 	pSMB->Reserved4 = 0;
 	pSMB->hdr.smb_buf_length += byte_count;
 	pSMB->ByteCount = cpu_to_le16(byte_count);
-	rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
-			 (struct smb_hdr *) pSMBr, &bytes_returned, 0);
+	rc = SendReceiveNoRsp(xid, tcon->ses, (struct smb_hdr *) pSMB, 0);
 	if (rc) {
 		cFYI(1,
 		     ("Send error in SetFileInfo (SetFileSize) = %d",
 		      rc));
 	}
 
-	if (pSMB)
-		cifs_small_buf_release(pSMB);
-
 	/* Note: On -EAGAIN error only caller can retry on handle based calls
 		since file handle passed in no longer valid */
 
@@ -4801,10 +4782,8 @@ CIFSSMBSetFileTimes(const int xid, struct cifsTconInfo *tcon,
 		    const FILE_BASIC_INFO *data, __u16 fid)
 {
 	struct smb_com_transaction2_sfi_req *pSMB  = NULL;
-	struct smb_com_transaction2_sfi_rsp *pSMBr = NULL;
 	char *data_offset;
 	int rc = 0;
-	int bytes_returned = 0;
 	__u16 params, param_offset, offset, byte_count, count;
 
 	cFYI(1, ("Set Times (via SetFileInfo)"));
@@ -4813,8 +4792,6 @@ CIFSSMBSetFileTimes(const int xid, struct cifsTconInfo *tcon,
 	if (rc)
 		return rc;
 
-	pSMBr = (struct smb_com_transaction2_sfi_rsp *)pSMB;
-
 	/* At this point there is no need to override the current pid
 	with the pid of the opener, but that could change if we someday
 	use an existing handle (rather than opening one on the fly) */
@@ -4854,14 +4831,11 @@ CIFSSMBSetFileTimes(const int xid, struct cifsTconInfo *tcon,
 	pSMB->hdr.smb_buf_length += byte_count;
 	pSMB->ByteCount = cpu_to_le16(byte_count);
 	memcpy(data_offset, data, sizeof(FILE_BASIC_INFO));
-	rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
-			 (struct smb_hdr *) pSMBr, &bytes_returned, 0);
+	rc = SendReceiveNoRsp(xid, tcon->ses, (struct smb_hdr *) pSMB, 0);
 	if (rc) {
 		cFYI(1, ("Send error in Set Time (SetFileInfo) = %d", rc));
 	}
 
-	cifs_small_buf_release(pSMB);
-
 	/* Note: On -EAGAIN error only caller can retry on handle based calls
 		since file handle passed in no longer valid */
 
@@ -5152,7 +5126,8 @@ int CIFSSMBNotify(const int xid, struct cifsTconInfo *tcon,
 	pSMB->ByteCount = 0;
 
 	rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
-			(struct smb_hdr *) pSMBr, &bytes_returned, -1);
+			 (struct smb_hdr *)pSMBr, &bytes_returned,
+			 CIFS_ASYNC_OP);
 	if (rc) {
 		cFYI(1, ("Error in Notify = %d", rc));
 	} else {