svn commit: r193735 - head/sys/fs/nfsclient

[Rick Macklem]

Author: rmacklem
Date: Mon Jun  8 18:41:23 2009
New Revision: 193735
URL: http://svn.freebsd.org/changeset/base/193735

Log:
  Fix nfscl_getcl() so that it doesn't crash when it is called to
  do an NFSv4 Close operation with the cred argument NULL. Also,
  clarify what NULL arguments mean in the function's comment.
  
  Approved by:	kib (mentor)

Modified:
  head/sys/fs/nfsclient/nfs_clstate.c

Modified: head/sys/fs/nfsclient/nfs_clstate.c
==============================================================================
--- head/sys/fs/nfsclient/nfs_clstate.c	Mon Jun  8 18:23:43 2009	(r193734)
+++ head/sys/fs/nfsclient/nfs_clstate.c	Mon Jun  8 18:41:23 2009	(r193735)
@@ -663,8 +663,9 @@ nfscl_openrelease(struct nfsclopen *op, 
  * client data structures to do the SetClientId/SetClientId_confirm,
  * but will release that lock and return the clientid with a refernce
  * count on it.
- * If the p argument is NULL, it will not do the SetClientId/Confirm
- * and the cred argument is not used, so it can be NULL too.
+ * If the "cred" argument is NULL, a new clientid should not be created.
+ * If the "p" argument is NULL, a SetClientID/SetClientIDConfirm cannot
+ * be done.
  * It always clpp with a reference count on it, unless returning an error.
  */
 APPLESTATIC int
@@ -672,28 +673,35 @@ nfscl_getcl(vnode_t vp, struct ucred *cr
     struct nfsclclient **clpp)
 {
 	struct nfsclclient *clp;
-	struct nfsclclient *newclp;
+	struct nfsclclient *newclp = NULL;
 	struct nfscllockowner *lp, *nlp;
 	struct nfsmount *nmp = VFSTONFS(vnode_mount(vp));
 	struct prison *pr;
 	char uuid[HOSTUUIDLEN];
 	int igotlock = 0, error, trystalecnt, clidinusedelay, i;
-	u_int16_t idlen;
+	u_int16_t idlen = 0;
 
-	pr = cred->cr_prison;
-	mtx_lock(&pr->pr_mtx);
-	strlcpy(uuid, pr->pr_uuid, sizeof uuid);
-	mtx_unlock(&pr->pr_mtx);
-	idlen = strlen(uuid);
-	if (idlen > 0)
-		idlen += sizeof (u_int64_t);
-	else
-		idlen += sizeof (u_int64_t) + 16;	/* 16 random bytes */
-	MALLOC(newclp, struct nfsclclient *, sizeof (struct nfsclclient) +
-	    idlen - 1, M_NFSCLCLIENT, M_WAITOK);
+	if (cred != NULL) {
+		pr = cred->cr_prison;
+		mtx_lock(&pr->pr_mtx);
+		strlcpy(uuid, pr->pr_uuid, sizeof uuid);
+		mtx_unlock(&pr->pr_mtx);
+		idlen = strlen(uuid);
+		if (idlen > 0)
+			idlen += sizeof (u_int64_t);
+		else
+			idlen += sizeof (u_int64_t) + 16; /* 16 random bytes */
+		MALLOC(newclp, struct nfsclclient *,
+		    sizeof (struct nfsclclient) + idlen - 1, M_NFSCLCLIENT,
+		    M_WAITOK);
+	}
 	NFSLOCKCLSTATE();
 	clp = nmp->nm_clp;
 	if (clp == NULL) {
+		if (newclp == NULL) {
+			NFSUNLOCKCLSTATE();
+			return (EACCES);
+		}
 		clp = newclp;
 		NFSBZERO((caddr_t)clp, sizeof(struct nfsclclient) + idlen - 1);
 		clp->nfsc_idlen = idlen;
@@ -714,7 +722,8 @@ nfscl_getcl(vnode_t vp, struct ucred *cr
 		nfscl_start_renewthread(clp);
 	} else {
 		NFSUNLOCKCLSTATE();
-		FREE((caddr_t)newclp, M_NFSCLCLIENT);
+		if (newclp != NULL)
+			FREE((caddr_t)newclp, M_NFSCLCLIENT);
 	}
 	NFSLOCKCLSTATE();
 	while ((clp->nfsc_flags & NFSCLFLAGS_HASCLIENTID) == 0 && !igotlock)
@@ -730,7 +739,7 @@ nfscl_getcl(vnode_t vp, struct ucred *cr
 	if ((clp->nfsc_flags & NFSCLFLAGS_HASCLIENTID) == 0) {
 		if (!igotlock)
 			panic("nfscl_clget");
-		if (p == NULL) {
+		if (p == NULL || cred == NULL) {
 			NFSLOCKCLSTATE();
 			nfsv4_unlock(&clp->nfsc_lock, 0);
 			NFSUNLOCKCLSTATE();
@@ -762,8 +771,8 @@ nfscl_getcl(vnode_t vp, struct ucred *cr
 			clidinusedelay = 120;
 		trystalecnt = 3;
 		do {
-			error = nfsrpc_setclient(VFSTONFS(vnode_mount(vp)), clp,
-			    cred, p);
+			error = nfsrpc_setclient(VFSTONFS(vnode_mount(vp)),
+			    clp, cred, p);
 			if (error == NFSERR_STALECLIENTID ||
 			    error == NFSERR_STALEDONTRECOVER ||
 			    error == NFSERR_CLIDINUSE) {