2 files changed, 39 insertions, 3 deletions

diff --git a/fs/coda/psdev.c b/fs/coda/psdev.c
index 241f7e04ad04..b4da2812499e 100644
--- a/fs/coda/psdev.c
+++ b/fs/coda/psdev.c
@@ -100,8 +100,12 @@ static ssize_t coda_psdev_write(struct file *file, const char __user *buf,
 	ssize_t retval = 0, count = 0;
 	int error;
 
+	/* make sure there is enough to copy out the (opcode, unique) values */
+	if (nbytes < (2 * sizeof(u_int32_t)))
+		return -EINVAL;
+
         /* Peek at the opcode, uniquefier */
-	if (copy_from_user(&hdr, buf, 2 * sizeof(u_long)))
+	if (copy_from_user(&hdr, buf, 2 * sizeof(u_int32_t)))
 	        return -EFAULT;
 
         if (DOWNCALL(hdr.opcode)) {
@@ -127,7 +131,7 @@ static ssize_t coda_psdev_write(struct file *file, const char __user *buf,
 		}
 
 		/* what downcall errors does Venus handle ? */
-		error = coda_downcall(vcp, hdr.opcode, dcbuf);
+		error = coda_downcall(vcp, hdr.opcode, dcbuf, nbytes);
 
 		CODA_FREE(dcbuf, nbytes);
 		if (error) {
diff --git a/fs/coda/upcall.c b/fs/coda/upcall.c
index 1175a1722411..cf1e662681a5 100644
--- a/fs/coda/upcall.c
+++ b/fs/coda/upcall.c
@@ -804,12 +804,44 @@ exit:
  *
  * CODA_REPLACE -- replace one CodaFid with another throughout the name cache */
 
-int coda_downcall(struct venus_comm *vcp, int opcode, union outputArgs *out)
+int coda_downcall(struct venus_comm *vcp, int opcode, union outputArgs *out,
+		  size_t nbytes)
 {
 	struct inode *inode = NULL;
 	struct CodaFid *fid = NULL, *newfid;
 	struct super_block *sb;
 
+	/*
+	 * Make sure we have received enough data from the cache
+	 * manager to populate the necessary fields in the buffer
+	 */
+	switch (opcode) {
+	case CODA_PURGEUSER:
+		if (nbytes < sizeof(struct coda_purgeuser_out))
+			return -EINVAL;
+		break;
+
+	case CODA_ZAPDIR:
+		if (nbytes < sizeof(struct coda_zapdir_out))
+			return -EINVAL;
+		break;
+
+	case CODA_ZAPFILE:
+		if (nbytes < sizeof(struct coda_zapfile_out))
+			return -EINVAL;
+		break;
+
+	case CODA_PURGEFID:
+		if (nbytes < sizeof(struct coda_purgefid_out))
+			return -EINVAL;
+		break;
+
+	case CODA_REPLACE:
+		if (nbytes < sizeof(struct coda_replace_out))
+			return -EINVAL;
+		break;
+	}
+
 	/* Handle invalidation requests. */
 	mutex_lock(&vcp->vc_mutex);
 	sb = vcp->vc_sb;