svn commit: r340850 - stable/12/sys/fs/nfs

[Ed Maste]

Author: emaste
Date: Fri Nov 23 20:31:27 2018
New Revision: 340850
URL: https://svnweb.freebsd.org/changeset/base/340850

Log:
  MFC r340662 (rmacklem):
  
  nfsm_advance() would panic() when the offs argument was negative.
  The code assumed that this would indicate a corrupted mbuf chain, but
  it could simply be caused by bogus RPC message data.
  This patch replaces the panic() with a printf() plus error return.

Modified:
  stable/12/sys/fs/nfs/nfs_commonsubs.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/sys/fs/nfs/nfs_commonsubs.c
==============================================================================
--- stable/12/sys/fs/nfs/nfs_commonsubs.c	Fri Nov 23 20:29:47 2018	(r340849)
+++ stable/12/sys/fs/nfs/nfs_commonsubs.c	Fri Nov 23 20:31:27 2018	(r340850)
@@ -725,10 +725,14 @@ nfsm_advance(struct nfsrv_descript *nd, int offs, int 
 	if (offs == 0)
 		goto out;
 	/*
-	 * A negative offs should be considered a serious problem.
+	 * A negative offs might indicate a corrupted mbuf chain and,
+	 * as such, a printf is logged.
 	 */
-	if (offs < 0)
-		panic("nfsrv_advance");
+	if (offs < 0) {
+		printf("nfsrv_advance: negative offs\n");
+		error = EBADRPC;
+		goto out;
+	}
 
 	/*
 	 * If left == -1, calculate it here.