bin/61666: mount_nfs parsing bug, segmentation fault

[Volker Stolz]

The following reply was made to PR bin/61666; it has been noted by GNATS.

From: Volker Stolz <stolz at i2.informatik.rwth-aachen.de>
To: freebsd-gnats-submit at FreeBSD.org, j at pureftpd.org
Cc:  
Subject: Re: bin/61666: mount_nfs parsing bug, segmentation fault
Date: Wed, 18 Feb 2004 12:48:38 +0100

 --cWoXeonUoKmBZSoM
 Content-Type: text/plain; charset=us-ascii
 Content-Disposition: inline
 
 The attached patch *should* help, but probably needs careful review.
 The option handling is mind-boggling anyway, especially w.r.t.
 'mountmode'. As 'getmntopts' and 'set_flags' are side-effect free,
 I'm confident it does the Right Thing. Patched and tested against
 -STABLE.
 
 Cheers,
   Volker
 -- 
 http://www-i2.informatik.rwth-aachen.de/stolz/ *** PGP *** S/MIME
 rage against the finite state machine 
 
 --cWoXeonUoKmBZSoM
 Content-Type: text/plain; charset=us-ascii
 Content-Disposition: attachment; filename=mount_nfs
 
 --- mount_nfs/mount_nfs.c	Tue Aug  5 10:56:03 2003
 +++ vs.mount_nfs/mount_nfs.c	Wed Feb 18 12:12:46 2004
 @@ -259,7 +259,7 @@
  	register struct nfs_args *nfsargsp;
  	struct nfs_args nfsargs;
  	struct nfsd_cargs ncd;
 -	int mntflags, altflags, nfssvc_flag, num;
 +	int mntflags, altflags, curflags, nfssvc_flag, num;
  	char *name, *p, *spec;
  	char mntpath[MAXPATHLEN];
  	struct vfsconf vfc;
 @@ -355,43 +355,47 @@
  			nfsargsp->flags &= ~NFSMNT_RESVPORT;
  			break;
  		case 'o':
 -			altflags = 0;
 +			altflags = curflags = 0;
 +			/* Get flags in current -o */
 +			getmntopts(optarg, mopts, &mntflags, &curflags);
  			set_flags(&altflags, &nfsargsp->flags, TRUE);
 +			/* NetBSD handles conflicting mountmodes much nicer */
  			if (mountmode == V2)
 -				altflags |= ALTF_NFSV2;
 +				curflags |= ALTF_NFSV2;
  			else if (mountmode == V3)
 -				altflags |= ALTF_NFSV3;
 -			getmntopts(optarg, mopts, &mntflags, &altflags);
 +				curflags |= ALTF_NFSV3;
 +			/* Join old and new flags */
 +			altflags = altflags | curflags;
  			set_flags(&altflags, &nfsargsp->flags, FALSE);
  			/*
 -			 * Handle altflags which don't map directly to
 +			 * Handle curflags which don't map directly to
  			 * mount flags.
  			 */
 -			if(altflags & ALTF_BG)
 +			if(curflags & ALTF_BG)
  				opflags |= BGRND;
 -			if(altflags & ALTF_MNTUDP)
 +			if(curflags & ALTF_MNTUDP)
  				mnttcp_ok = 0;
 -			if(altflags & ALTF_TCP) {
 +			if(curflags & ALTF_TCP) {
  				nfsargsp->sotype = SOCK_STREAM;
  				nfsproto = IPPROTO_TCP;
  			}
 -			if(altflags & ALTF_PORT)
 +			if(curflags & ALTF_PORT)
  				port_no = atoi(strstr(optarg, "port=") + 5);
  			mountmode = ANY;
 -			if(altflags & ALTF_NFSV2)
 +			if(curflags & ALTF_NFSV2)
  				mountmode = V2;
 -			if(altflags & ALTF_NFSV3)
 +			if(curflags & ALTF_NFSV3)
  				mountmode = V3;
 -			if(altflags & ALTF_ACREGMIN)
 +			if(curflags & ALTF_ACREGMIN)
  				nfsargsp->acregmin = atoi(strstr(optarg,
  				    "acregmin=") + 9);
 -			if(altflags & ALTF_ACREGMAX)
 +			if(curflags & ALTF_ACREGMAX)
  				nfsargsp->acregmax = atoi(strstr(optarg,
  				    "acregmax=") + 9);
 -			if(altflags & ALTF_ACDIRMIN)
 +			if(curflags & ALTF_ACDIRMIN)
  				nfsargsp->acdirmin = atoi(strstr(optarg,
  				    "acdirmin=") + 9);
 -			if(altflags & ALTF_ACDIRMAX)
 +			if(curflags & ALTF_ACDIRMAX)
  				nfsargsp->acdirmax = atoi(strstr(optarg,
  				    "acdirmax=") + 9);
  			break;
 
 --cWoXeonUoKmBZSoM--