[PATCH v2] cifs: setcifsacl - Send the actual (security descriptor) buffer size instead of the pre-allocated size

[shirishpargaonkar-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org]

From: Shirish Pargaonkar <shirishpargaonkar-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

Some SMB servers such as HDS HNAS (Hitachi NAS) return error
NT Status: STATUS_INVALID_SECURITY_DESCR (0xc0000079)
during set cifs acl operation.

This happens due to mismatch in the size of actual security descriptor
being set versus the size of the security descriptor stated in the request.

Instead of sending allocated buffer size of a security descriptor,
send the actual size of the security descriptor during set cifs acl
operation.


Signed-off-by: Shirish Pargaonkar <shirishpargaonkar-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

---
 setcifsacl.c | 61 ++++++++++++++++++++++++++++++++++++++----------------------
 1 file changed, 39 insertions(+), 22 deletions(-)

diff --git a/setcifsacl.c b/setcifsacl.c
index 7eeeaa6..ba34403 100644
--- a/setcifsacl.c
+++ b/setcifsacl.c
@@ -50,24 +50,34 @@ enum setcifsacl_actions {
 static void *plugin_handle;
 static bool plugin_loaded;
 
-static void
+static int
 copy_cifs_sid(struct cifs_sid *dst, const struct cifs_sid *src)
 {
-	int i;
+	int i, size = 0;
 
 	dst->revision = src->revision;
+	size += sizeof(uint8_t);
+
 	dst->num_subauth = src->num_subauth;
+	size += sizeof(uint8_t);
+
 	for (i = 0; i < NUM_AUTHS; i++)
 		dst->authority[i] = src->authority[i];
+	size += (sizeof(uint8_t) * NUM_AUTHS);
+
 	for (i = 0; i < src->num_subauth; i++)
 		dst->sub_auth[i] = src->sub_auth[i];
+	size += (sizeof(uint32_t) * src->num_subauth);
+
+	return size;
 }
 
-static void
+static ssize_t
 copy_sec_desc(const struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,
 		int numaces, int acessize)
 {
-	int osidsoffset, gsidsoffset, dacloffset;
+	int size, osidsoffset, gsidsoffset, dacloffset;
+	ssize_t bufsize;
 	struct cifs_sid *owner_sid_ptr, *group_sid_ptr;
 	struct cifs_sid *nowner_sid_ptr, *ngroup_sid_ptr;
 	struct cifs_ctrl_acl *dacl_ptr, *ndacl_ptr;
@@ -77,30 +87,36 @@ copy_sec_desc(const struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,
 	gsidsoffset = le32toh(pntsd->gsidoffset);
 	dacloffset = le32toh(pntsd->dacloffset);
 
+	size = sizeof(struct cifs_ntsd);
 	pnntsd->revision = pntsd->revision;
 	pnntsd->type = pntsd->type;
 	pnntsd->osidoffset = pntsd->osidoffset;
 	pnntsd->gsidoffset = pntsd->gsidoffset;
 	pnntsd->dacloffset = pntsd->dacloffset;
+	bufsize = size;
 
 	dacl_ptr = (struct cifs_ctrl_acl *)((char *)pntsd + dacloffset);
 	ndacl_ptr = (struct cifs_ctrl_acl *)((char *)pnntsd + dacloffset);
 
+	size = acessize + sizeof(struct cifs_ctrl_acl);
 	ndacl_ptr->revision = dacl_ptr->revision;
-	ndacl_ptr->size = htole16(acessize + sizeof(struct cifs_ctrl_acl));
+	ndacl_ptr->size = htole16(size);
 	ndacl_ptr->num_aces = htole32(numaces);
+	bufsize += size;
 
 	/* copy owner sid */
 	owner_sid_ptr = (struct cifs_sid *)((char *)pntsd + osidsoffset);
 	nowner_sid_ptr = (struct cifs_sid *)((char *)pnntsd + osidsoffset);
-	copy_cifs_sid(nowner_sid_ptr, owner_sid_ptr);
+	size = copy_cifs_sid(nowner_sid_ptr, owner_sid_ptr);
+	bufsize += size;
 
 	/* copy group sid */
 	group_sid_ptr = (struct cifs_sid *)((char *)pntsd + gsidsoffset);
 	ngroup_sid_ptr = (struct cifs_sid *)((char *)pnntsd + gsidsoffset);
-	copy_cifs_sid(ngroup_sid_ptr, group_sid_ptr);
+	size = copy_cifs_sid(ngroup_sid_ptr, group_sid_ptr);
+	bufsize += size;
 
-	return;
+	return bufsize;
 }
 
 static int
@@ -156,10 +172,10 @@ compare_aces(struct cifs_ace *sace, struct cifs_ace *dace, int compflags)
 }
 
 static int
-get_sec_desc_size(struct cifs_ntsd *pntsd, struct cifs_ntsd **npntsd,
-			int aces, ssize_t *bufsize, size_t *acesoffset)
+alloc_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd **npntsd,
+			int aces, size_t *acesoffset)
 {
-	unsigned int size, acessize, dacloffset;
+	unsigned int size, acessize, bufsize, dacloffset;
 
 	size = sizeof(struct cifs_ntsd) +
 		2 * sizeof(struct cifs_sid) +
@@ -169,9 +185,9 @@ get_sec_desc_size(struct cifs_ntsd *pntsd, struct cifs_ntsd **npntsd,
 
 	*acesoffset = dacloffset + sizeof(struct cifs_ctrl_acl);
 	acessize = aces * sizeof(struct cifs_ace);
-	*bufsize = size + acessize;
+	bufsize = size + acessize;
 
-	*npntsd = malloc(*bufsize);
+	*npntsd = malloc(bufsize);
 	if (!*npntsd) {
 		printf("%s: Memory allocation failure", __func__);
 		return errno;
@@ -188,7 +204,7 @@ ace_set(struct cifs_ntsd *pntsd, struct cifs_ntsd **npntsd, ssize_t *bufsize,
 	size_t acesoffset;
 	char *acesptr;
 
-	rc = get_sec_desc_size(pntsd, npntsd, numcaces, bufsize, &acesoffset);
+	rc = alloc_sec_desc(pntsd, npntsd, numcaces, &acesoffset);
 	if (rc)
 		return rc;
 
@@ -198,9 +214,8 @@ ace_set(struct cifs_ntsd *pntsd, struct cifs_ntsd **npntsd, ssize_t *bufsize,
 		acessize += size;
 		acesptr += size;
 	}
-	copy_sec_desc(pntsd, *npntsd, numcaces, acessize);
-	acesptr = (char *)*npntsd + acesoffset;
 
+	*bufsize = copy_sec_desc(pntsd, *npntsd, numcaces, acessize);
 
 	return 0;
 }
@@ -215,7 +230,7 @@ ace_add(struct cifs_ntsd *pntsd, struct cifs_ntsd **npntsd, ssize_t *bufsize,
 	char *acesptr;
 
 	numaces = numfaces + numcaces;
-	rc = get_sec_desc_size(pntsd, npntsd, numaces, bufsize, &acesoffset);
+	rc = alloc_sec_desc(pntsd, npntsd, numaces, &acesoffset);
 	if (rc)
 		return rc;
 
@@ -230,7 +245,8 @@ ace_add(struct cifs_ntsd *pntsd, struct cifs_ntsd **npntsd, ssize_t *bufsize,
 		acesptr += size;
 		acessize += size;
 	}
-	copy_sec_desc(pntsd, *npntsd, numaces, acessize);
+
+	*bufsize = copy_sec_desc(pntsd, *npntsd, numaces, acessize);
 
 	return 0;
 }
@@ -249,7 +265,7 @@ ace_modify(struct cifs_ntsd *pntsd, struct cifs_ntsd **npntsd, ssize_t *bufsize,
 		return -1;
 	}
 
-	rc = get_sec_desc_size(pntsd, npntsd, numfaces, bufsize, &acesoffset);
+	rc = alloc_sec_desc(pntsd, npntsd, numfaces, &acesoffset);
 	if (rc)
 		return rc;
 
@@ -270,7 +286,7 @@ ace_modify(struct cifs_ntsd *pntsd, struct cifs_ntsd **npntsd, ssize_t *bufsize,
 		acessize += size;
 	}
 
-	copy_sec_desc(pntsd, *npntsd, numfaces, acessize);
+	*bufsize = copy_sec_desc(pntsd, *npntsd, numfaces, acessize);
 
 	return 0;
 }
@@ -294,7 +310,7 @@ ace_delete(struct cifs_ntsd *pntsd, struct cifs_ntsd **npntsd, ssize_t *bufsize,
 		return -1;
 	}
 
-	rc = get_sec_desc_size(pntsd, npntsd, numfaces, bufsize, &acesoffset);
+	rc = alloc_sec_desc(pntsd, npntsd, numfaces, &acesoffset);
 	if (rc)
 		return rc;
 
@@ -317,7 +333,8 @@ ace_delete(struct cifs_ntsd *pntsd, struct cifs_ntsd **npntsd, ssize_t *bufsize,
 		printf("%s: Nothing to delete\n", __func__);
 		return 1;
 	}
-	copy_sec_desc(pntsd, *npntsd, numaces, acessize);
+
+	*bufsize = copy_sec_desc(pntsd, *npntsd, numaces, acessize);
 
 	return 0;
 }
-- 
1.9.1