Commit 184ed211 authored by Steve French's avatar Steve French
Browse files

[CIFS] Fix large (ie over 64K for MaxCIFSBufSize) buffer case for wrapping 


bcc on read response and for wrapping sessionsetup maxbufsize field

Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent 5d2f248a

fs/cifs/CHANGES

+5 −1
Original line number Diff line number Diff line
@@ -2,7 +2,11 @@ Version 1.41 
------------

Fix NTLMv2 security (can be enabled in /proc/fs/cifs) so customers can

configure stronger authentication.  Fix sfu symlinks so they can

be followed (not just recognized).

be followed (not just recognized).  Fix wraparound of bcc on

read responses when buffer size over 64K and also fix wrap of

max smb buffer size when CIFSMaxBufSize over 64K.  Fix oops in

cifs_user_read and cifs_readpages (when EAGAIN on send of smb

on socket is returned over and over)



Version 1.40

------------

fs/cifs/connect.c

+3 −1
Original line number Diff line number Diff line
@@ -2278,6 +2278,8 @@ CIFSSpnegoSessSetup(unsigned int xid, struct cifsSesInfo *ses, 
	smb_buffer->Mid = GetNextMid(ses->server);

	pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;

	pSMB->req.AndXCommand = 0xFF;

	if(ses->server->maxBuf > 64*1024)

		ses->server->maxBuf = (64*1023);

	pSMB->req.MaxBufferSize = cpu_to_le16(ses->server->maxBuf);

	pSMB->req.MaxMpxCount = cpu_to_le16(ses->server->maxReq);

fs/cifs/misc.c

+16 −11
Original line number Diff line number Diff line
@@ -421,9 +421,7 @@ checkSMB(struct smb_hdr *smb, __u16 mid, int length) 
{

	__u32 len = smb->smb_buf_length;

	__u32 clc_len;  /* calculated length */

	cFYI(0,

	     ("Entering checkSMB with Length: %x, smb_buf_length: %x",

	      length, len));

	cFYI(0, ("checkSMB Length: 0x%x, smb_buf_length: 0x%x", length, len));

	if (((unsigned int)length < 2 + sizeof (struct smb_hdr)) ||

	    (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4)) {

		if ((unsigned int)length < 2 + sizeof (struct smb_hdr)) {
@@ -435,13 +433,9 @@ checkSMB(struct smb_hdr *smb, __u16 mid, int length) 
			} else {

				cERROR(1, ("Length less than smb header size"));

			}



		}

		if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4)

			cERROR(1,

			       ("smb_buf_length greater than MaxBufSize"));

		cERROR(1,

		       ("bad smb detected. Illegal length. mid=%d",

			cERROR(1, ("smb length greater than MaxBufSize, mid=%d",

				   smb->Mid));

		return 1;

	}
@@ -449,8 +443,19 @@ checkSMB(struct smb_hdr *smb, __u16 mid, int length) 
	if (checkSMBhdr(smb, mid))

		return 1;

	clc_len = smbCalcSize_LE(smb);

	if ((4 + len != clc_len)

	    || (4 + len != (unsigned int)length)) {



	if(4 + len != (unsigned int)length) {

		cERROR(1, ("Length read does not match RFC1001 length %d",len));

		return 1;

	}



	if (4 + len != clc_len) {

		/* check if bcc wrapped around for large read responses */

		if((len > 64 * 1024) && (len > clc_len)) {

			/* check if lengths match mod 64K */

			if(((4 + len) & 0xFFFF) == (clc_len & 0xFFFF))

				return 0; /* bcc wrapped */			

		}

		cERROR(1, ("Calculated size 0x%x vs actual length 0x%x",

				clc_len, 4 + len));

		cERROR(1, ("bad smb size detected for Mid=%d", smb->Mid));