lockd: Don't expose the process pid to the NLM server

Instead we use the nlm_lockowner->pid.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/lockd/clntlock.c

@@ -125,7 +125,15 @@ u32 nlmclnt_grant(const struct sockaddr_in *addr, const struct nlm_lock *lock)
 	list_for_each_entry(block, &nlm_blocked, b_list) {
 		struct file_lock *fl_blocked = block->b_lock;
 
-		if (!nlm_compare_locks(fl_blocked, fl))
+		if (fl_blocked->fl_start != fl->fl_start)
+			continue;
+		if (fl_blocked->fl_end != fl->fl_end)
+			continue;
+		/*
+		 * Careful! The NLM server will return the 32-bit "pid" that
+		 * we put on the wire: in this case the lockowner "pid".
+		 */
+		if (fl_blocked->fl_u.nfs_fl.owner->pid != lock->svid)
 			continue;
 		if (!nlm_cmp_addr(&block->b_host->h_addr, addr))
 			continue;

fs/lockd/clntproc.c

@@ -132,8 +132,10 @@ static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl)
 	memcpy(&lock->fh, NFS_FH(fl->fl_file->f_dentry->d_inode), sizeof(struct nfs_fh));
 	lock->caller  = system_utsname.nodename;
 	lock->oh.data = req->a_owner;
-	lock->oh.len  = sprintf(req->a_owner, "%d@%s",
-				current->pid, system_utsname.nodename);
+	lock->oh.len  = snprintf(req->a_owner, sizeof(req->a_owner), "%u@%s",
+				(unsigned int)fl->fl_u.nfs_fl.owner->pid,
+				system_utsname.nodename);
+	lock->svid = fl->fl_u.nfs_fl.owner->pid;
 	locks_copy_lock(&lock->fl, fl);
 }
 
@@ -159,6 +161,7 @@ nlmclnt_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock)
 
 	/* set default data area */
 	call->a_args.lock.oh.data = call->a_owner;
+	call->a_args.lock.svid = lock->fl.fl_pid;
 
 	if (lock->oh.len > NLMCLNT_OHSIZE) {
 		void *data = kmalloc(lock->oh.len, GFP_KERNEL);

fs/lockd/svclock.c

@@ -397,6 +397,7 @@ nlmsvc_testlock(struct nlm_file *file, struct nlm_lock *lock,
 				(long long)fl->fl_end);
 		conflock->caller = "somehost";	/* FIXME */
 		conflock->oh.len = 0;		/* don't return OH info */
+		conflock->svid = fl->fl_pid;
 		conflock->fl = *fl;
 		return nlm_lck_denied;
 	}

fs/lockd/xdr.c

@@ -131,10 +131,11 @@ nlm_decode_lock(u32 *p, struct nlm_lock *lock)
 	 || !(p = nlm_decode_fh(p, &lock->fh))
 	 || !(p = nlm_decode_oh(p, &lock->oh)))
 		return NULL;
+	lock->svid  = ntohl(*p++);
 
 	locks_init_lock(fl);
 	fl->fl_owner = current->files;
-	fl->fl_pid   = ntohl(*p++);
+	fl->fl_pid   = (pid_t)lock->svid;
 	fl->fl_flags = FL_POSIX;
 	fl->fl_type  = F_RDLCK;		/* as good as anything else */
 	start = ntohl(*p++);
@@ -174,7 +175,7 @@ nlm_encode_lock(u32 *p, struct nlm_lock *lock)
 	else
 		len = loff_t_to_s32(fl->fl_end - fl->fl_start + 1);
 
-	*p++ = htonl(fl->fl_pid);
+	*p++ = htonl(lock->svid);
 	*p++ = htonl(start);
 	*p++ = htonl(len);
 
@@ -197,7 +198,7 @@ nlm_encode_testres(u32 *p, struct nlm_res *resp)
 		struct file_lock	*fl = &resp->lock.fl;
 
 		*p++ = (fl->fl_type == F_RDLCK)? xdr_zero : xdr_one;
-		*p++ = htonl(fl->fl_pid);
+		*p++ = htonl(resp->lock.svid);
 
 		/* Encode owner handle. */
 		if (!(p = xdr_encode_netobj(p, &resp->lock.oh)))
@@ -298,7 +299,8 @@ nlmsvc_decode_shareargs(struct svc_rqst *rqstp, u32 *p, nlm_args *argp)
 
 	memset(lock, 0, sizeof(*lock));
 	locks_init_lock(&lock->fl);
-	lock->fl.fl_pid = ~(u32) 0;
+	lock->svid = ~(u32) 0;
+	lock->fl.fl_pid = (pid_t)lock->svid;
 
 	if (!(p = nlm_decode_cookie(p, &argp->cookie))
 	 || !(p = xdr_decode_string_inplace(p, &lock->caller,
@@ -415,7 +417,8 @@ nlmclt_decode_testres(struct rpc_rqst *req, u32 *p, struct nlm_res *resp)
 		memset(&resp->lock, 0, sizeof(resp->lock));
 		locks_init_lock(fl);
 		excl = ntohl(*p++);
-		fl->fl_pid = ntohl(*p++);
+		resp->lock.svid = ntohl(*p++);
+		fl->fl_pid = (pid_t)resp->lock.svid;
 		if (!(p = nlm_decode_oh(p, &resp->lock.oh)))
 			return -EIO;
 

fs/lockd/xdr4.c

@@ -130,10 +130,11 @@ nlm4_decode_lock(u32 *p, struct nlm_lock *lock)
 	 || !(p = nlm4_decode_fh(p, &lock->fh))
 	 || !(p = nlm4_decode_oh(p, &lock->oh)))
 		return NULL;
+	lock->svid  = ntohl(*p++);
 
 	locks_init_lock(fl);
 	fl->fl_owner = current->files;
-	fl->fl_pid   = ntohl(*p++);
+	fl->fl_pid   = (pid_t)lock->svid;
 	fl->fl_flags = FL_POSIX;
 	fl->fl_type  = F_RDLCK;		/* as good as anything else */
 	p = xdr_decode_hyper(p, &start);
@@ -167,7 +168,7 @@ nlm4_encode_lock(u32 *p, struct nlm_lock *lock)
 	 || (fl->fl_end > NLM4_OFFSET_MAX && fl->fl_end != OFFSET_MAX))
 		return NULL;
 
-	*p++ = htonl(fl->fl_pid);
+	*p++ = htonl(lock->svid);
 
 	start = loff_t_to_s64(fl->fl_start);
 	if (fl->fl_end == OFFSET_MAX)
@@ -198,7 +199,7 @@ nlm4_encode_testres(u32 *p, struct nlm_res *resp)
 		struct file_lock	*fl = &resp->lock.fl;
 
 		*p++ = (fl->fl_type == F_RDLCK)? xdr_zero : xdr_one;
-		*p++ = htonl(fl->fl_pid);
+		*p++ = htonl(resp->lock.svid);
 
 		/* Encode owner handle. */
 		if (!(p = xdr_encode_netobj(p, &resp->lock.oh)))
@@ -212,8 +213,8 @@ nlm4_encode_testres(u32 *p, struct nlm_res *resp)
 
 		p = xdr_encode_hyper(p, start);
 		p = xdr_encode_hyper(p, len);
-		dprintk("xdr: encode_testres (status %d pid %d type %d start %Ld end %Ld)\n",
-			resp->status, fl->fl_pid, fl->fl_type,
+		dprintk("xdr: encode_testres (status %u pid %d type %d start %Ld end %Ld)\n",
+			resp->status, (int)resp->lock.svid, fl->fl_type,
 			(long long)fl->fl_start,  (long long)fl->fl_end);
 	}
 
@@ -303,7 +304,8 @@ nlm4svc_decode_shareargs(struct svc_rqst *rqstp, u32 *p, nlm_args *argp)
 
 	memset(lock, 0, sizeof(*lock));
 	locks_init_lock(&lock->fl);
-	lock->fl.fl_pid = ~(u32) 0;
+	lock->svid = ~(u32) 0;
+	lock->fl.fl_pid = (pid_t)lock->svid;
 
 	if (!(p = nlm4_decode_cookie(p, &argp->cookie))
 	 || !(p = xdr_decode_string_inplace(p, &lock->caller,
@@ -420,7 +422,8 @@ nlm4clt_decode_testres(struct rpc_rqst *req, u32 *p, struct nlm_res *resp)
 		memset(&resp->lock, 0, sizeof(resp->lock));
 		locks_init_lock(fl);
 		excl = ntohl(*p++);
-		fl->fl_pid = ntohl(*p++);
+		resp->lock.svid = ntohl(*p++);
+		fl->fl_pid = (pid_t)resp->lock.svid;
 		if (!(p = nlm4_decode_oh(p, &resp->lock.oh)))
 			return -EIO;
 

include/linux/lockd/xdr.h

@@ -28,6 +28,7 @@ struct nlm_lock {
 	int			len; 	/* length of "caller" */
 	struct nfs_fh		fh;
 	struct xdr_netobj	oh;
+	u32			svid;
 	struct file_lock	fl;
 };