[CIFS] acl support part 6

Acked-by: Shirish Pargaonkar <shirishp@us.ibm.com>
CC: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 40 insertions, 15 deletions

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 61d24f6ee64e..cc17e98991f3 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -2526,12 +2526,15 @@ smb_init_ntransact(const __u16 sub_command, const int setup_count,
 
 static int
 validate_ntransact(char *buf, char **ppparm, char **ppdata,
-		   int *pdatalen, int *pparmlen)
+		   __u32 *pdatalen, __u32 *pparmlen)
 {
 	char *end_of_smb;
 	__u32 data_count, data_offset, parm_count, parm_offset;
 	struct smb_com_ntransact_rsp *pSMBr;
 
+	*pdatalen = 0;
+	*pparmlen = 0;
+
 	if (buf == NULL)
 		return -EINVAL;
 
@@ -2568,6 +2571,8 @@ validate_ntransact(char *buf, char **ppparm, char **ppdata,
 		cFYI(1, ("parm count and data count larger than SMB"));
 		return -EINVAL;
 	}
+	*pdatalen = data_count;
+	*pparmlen = parm_count;
 	return 0;
 }
 #endif /* CIFS_EXPERIMENTAL */
@@ -3069,8 +3074,7 @@ GetExtAttrOut:
 /* Get Security Descriptor (by handle) from remote server for a file or dir */
 int
 CIFSSMBGetCIFSACL(const int xid, struct cifsTconInfo *tcon, __u16 fid,
-		/* BB fix up return info */ char *acl_inf, const int buflen,
-		  const int acl_type)
+		  struct cifs_ntsd **acl_inf, __u32 *pbuflen)
 {
 	int rc = 0;
 	int buf_type = 0;
@@ -3079,6 +3083,9 @@ CIFSSMBGetCIFSACL(const int xid, struct cifsTconInfo *tcon, __u16 fid,
 
 	cFYI(1, ("GetCifsACL"));
 
+	*pbuflen = 0;
+	*acl_inf = NULL;
+
 	rc = smb_init_ntransact(NT_TRANSACT_QUERY_SECURITY_DESC, 0,
 			8 /* parm len */, tcon, (void **) &pSMB);
 	if (rc)
@@ -3101,34 +3108,52 @@ CIFSSMBGetCIFSACL(const int xid, struct cifsTconInfo *tcon, __u16 fid,
 	if (rc) {
 		cFYI(1, ("Send error in QuerySecDesc = %d", rc));
 	} else {                /* decode response */
-		struct cifs_ntsd *psec_desc;
 		__le32 * parm;
-		int parm_len;
-		int data_len;
-		int acl_len;
+		__u32 parm_len;
+		__u32 acl_len;
 		struct smb_com_ntransact_rsp *pSMBr;
+		char *pdata;
 
 /* validate_nttransact */
 		rc = validate_ntransact(iov[0].iov_base, (char **)&parm,
-					(char **)&psec_desc,
-					&parm_len, &data_len);
+					&pdata, &parm_len, pbuflen);
 		if (rc)
 			goto qsec_out;
 		pSMBr = (struct smb_com_ntransact_rsp *)iov[0].iov_base;
 
-		cFYI(1, ("smb %p parm %p data %p", pSMBr, parm, psec_desc));
+		cFYI(1, ("smb %p parm %p data %p", pSMBr, parm, *acl_inf));
 
 		if (le32_to_cpu(pSMBr->ParameterCount) != 4) {
 			rc = -EIO;      /* bad smb */
+			*pbuflen = 0;
 			goto qsec_out;
 		}
 
 /* BB check that data area is minimum length and as big as acl_len */
 
 		acl_len = le32_to_cpu(*parm);
-		/* BB check if (acl_len > bufsize) */
+		if (acl_len != *pbuflen) {
+			cERROR(1, ("acl length %d does not match %d",
+				   acl_len, *pbuflen));
+			if (*pbuflen > acl_len)
+				*pbuflen = acl_len;
+		}
 
-		parse_sec_desc(psec_desc, acl_len);
+		/* check if buffer is big enough for the acl
+		   header followed by the smallest SID */
+		if ((*pbuflen < sizeof(struct cifs_ntsd) + 8) ||
+		    (*pbuflen >= 64 * 1024)) {
+			cERROR(1, ("bad acl length %d", *pbuflen));
+			rc = -EINVAL;
+			*pbuflen = 0;
+		} else {
+			*acl_inf = kmalloc(*pbuflen, GFP_KERNEL);
+			if (*acl_inf == NULL) {
+				*pbuflen = 0;
+				rc = -ENOMEM;
+			}
+			memcpy(*acl_inf, pdata, *pbuflen);
+		}
 	}
 qsec_out:
 	if (buf_type == CIFS_SMALL_BUFFER)
@@ -3383,7 +3408,7 @@ UnixQPathInfoRetry:
 			memcpy((char *) pFindData,
 			       (char *) &pSMBr->hdr.Protocol +
 			       data_offset,
-			       sizeof (FILE_UNIX_BASIC_INFO));
+			       sizeof(FILE_UNIX_BASIC_INFO));
 		}
 	}
 	cifs_buf_release(pSMB);
@@ -3651,7 +3676,7 @@ int CIFSFindNext(const int xid, struct cifsTconInfo *tcon,
 	pSMB->SubCommand = cpu_to_le16(TRANS2_FIND_NEXT);
 	pSMB->SearchHandle = searchHandle;      /* always kept as le */
 	pSMB->SearchCount =
-		cpu_to_le16(CIFSMaxBufSize / sizeof (FILE_UNIX_INFO));
+		cpu_to_le16(CIFSMaxBufSize / sizeof(FILE_UNIX_INFO));
 	pSMB->InformationLevel = cpu_to_le16(psrch_inf->info_level);
 	pSMB->ResumeKey = psrch_inf->resume_key;
 	pSMB->SearchFlags =
@@ -4333,7 +4358,7 @@ QFSDeviceRetry:
 	} else {		/* decode response */
 		rc = validate_t2((struct smb_t2_rsp *)pSMBr);
 
-		if (rc || (pSMBr->ByteCount < sizeof (FILE_SYSTEM_DEVICE_INFO)))
+		if (rc || (pSMBr->ByteCount < sizeof(FILE_SYSTEM_DEVICE_INFO)))
 			rc = -EIO;	/* bad smb */
 		else {
 			__u16 data_offset = le16_to_cpu(pSMBr->t2.DataOffset);