>Number: 170413
>Category: bin
>Synopsis: mountd: correct handling of -alldirs option and segmentation
>fault for -sec option
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Mon Aug 06 10:40:05 UTC 2012
>Closed-Date:
>Last-Modified:
>Originator: Andrey Simonenko
>Release: FreeBSD 10.0-CURRENT amd64
>Organization:
[email protected]
>Environment:
>Description:
According to the exports(5) manual page if a line starts with a single
pathname of the root of the file system followed by the -alldirs option.
This option allows to specify that this is a file system export, does not
matter whether it is mounted right now or will be mounted in future.
mountd starting from the 1.84 revision of the usr.sbin/mountd/mountd.c
file ignores the -alldirs option (> 5 years ago). It silently treats
the given pathname as a directory name and exports the entire file
system this directory belongs to. Actually it has to export the given
pathname only if it is a mount point. This is a security issue, since
mountd violates exports(5) rules.
Also the following update corrects segmentation fault if the -sec option
is given without an argument.
>How-To-Repeat:
Create the /etc/exports file with this content:
/cdrom -alldirs
Suppose /cdrom is not a mount point, now run mountd and try to mount
the <server>:/ NFS export, you will get access to the root file system.
>Fix:
--- mountd.c.orig 2012-01-20 13:19:39.000000000 +0200
+++ mountd.c 2012-08-06 12:50:52.000000000 +0300
@@ -174,8 +174,8 @@ static void complete_service(struct netc
static void clearout_service(void);
void del_mlist(char *hostp, char *dirp);
struct dirlist *dirp_search(struct dirlist *, char *);
-int do_mount(struct exportlist *, struct grouplist *, int,
- struct xucred *, char *, int, struct statfs *);
+static int do_mount(const struct exportlist *, const struct grouplist *, int,
+ const struct xucred *, const char *, struct statfs *);
int do_opt(char **, char **, struct exportlist *, struct grouplist *,
int *, int *, struct xucred *);
struct exportlist *ex_search(fsid_t *);
@@ -1333,7 +1333,7 @@ get_exportlist_one(void)
struct statfs fsb;
struct xucred anon;
char *cp, *endcp, *dirp, *hst, *usr, *dom, savedc;
- int len, has_host, exflags, got_nondir, dirplen, netgrp;
+ int len, has_host, exflags, got_nondir, netgrp;
v4root_phase = 0;
dirhead = (struct dirlist *)NULL;
@@ -1473,7 +1473,6 @@ get_exportlist_one(void)
* Add dirpath to export mount point.
*/
dirp = add_expdir(&dirhead, cp, len);
- dirplen = len;
}
} else {
getexp_err(ep, tgrp);
@@ -1567,8 +1566,7 @@ get_exportlist_one(void)
*/
grp = tgrp;
do {
- if (do_mount(ep, grp, exflags, &anon, dirp, dirplen,
- &fsb)) {
+ if (do_mount(ep, grp, exflags, &anon, dirp, &fsb)) {
getexp_err(ep, tgrp);
goto nextline;
}
@@ -2183,7 +2181,7 @@ do_opt(char **cpp, char **endcpp, struct
ep->ex_indexfile = strdup(cpoptarg);
} else if (!strcmp(cpopt, "quiet")) {
opt_flags |= OP_QUIET;
- } else if (!strcmp(cpopt, "sec")) {
+ } else if (cpoptarg != NULL && !strcmp(cpopt, "sec")) {
if (parsesec(cpoptarg, ep))
return (1);
opt_flags |= OP_SEC;
@@ -2330,62 +2328,64 @@ out_of_mem(void)
* Do the nmount() syscall with the update flag to push the export info into
* the kernel.
*/
-int
-do_mount(struct exportlist *ep, struct grouplist *grp, int exflags,
- struct xucred *anoncrp, char *dirp, int dirplen, struct statfs *fsb)
+static int
+do_mount(const struct exportlist *ep, const struct grouplist *grp, int exflags,
+ const struct xucred *anoncrp, const char *dirp, struct statfs *fsb)
{
- struct statfs fsb1;
- struct addrinfo *ai;
- struct export_args ea, *eap;
- char errmsg[255];
- char *cp;
- int done;
- char savedc;
- struct iovec *iov;
- int i, iovlen;
- int ret;
+ char errmsg[256];
struct nfsex_args nfsea;
+ const struct addrinfo *ai;
+ struct export_args *eap;
+ struct iovec *iov;
+ int i, ret, iovlen;
- if (run_v4server > 0)
- eap = &nfsea.export;
- else
- eap = &ea;
-
- cp = NULL;
- savedc = '\0';
iov = NULL;
- iovlen = 0;
- ret = 0;
+ eap = &nfsea.export;
+ if (v4root_phase == 0) {
+ if ((opt_flags & OP_ALLDIRS) &&
+ strcmp(dirp, fsb->f_mntonname) != 0) {
+ if (!(opt_flags & OP_QUIET))
+ syslog(LOG_ERR, "-alldirs requested but %s "
+ "is not a file system mount point", dirp);
+ return (1);
+ }
+ bzero(errmsg, sizeof(errmsg));
+ iovlen = 0;
+ build_iovec(&iov, &iovlen, "fstype", fsb->f_fstypename,
+ (size_t)-1);
+ build_iovec(&iov, &iovlen, "fspath", fsb->f_mntonname,
+ (size_t)-1);
+ build_iovec(&iov, &iovlen, "from", fsb->f_mntfromname,
+ (size_t)-1);
+ build_iovec(&iov, &iovlen, "update", NULL, 0);
+ build_iovec(&iov, &iovlen, "export", eap, sizeof(*eap));
+ build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg));
+ if (iovlen < 0) {
+ syslog(LOG_ERR, "build_iovec: %m");
+ return (1);
+ }
+ } else {
+ if (run_v4server == 0)
+ return (0);
+ nfsea.fspec = v4root_dirpath;
+ }
- bzero(eap, sizeof (struct export_args));
- bzero(errmsg, sizeof(errmsg));
+ bzero(eap, sizeof(*eap));
eap->ex_flags = exflags;
eap->ex_anon = *anoncrp;
eap->ex_indexfile = ep->ex_indexfile;
- if (grp->gr_type == GT_HOST)
- ai = grp->gr_ptr.gt_addrinfo;
- else
- ai = NULL;
- eap->ex_numsecflavors = ep->ex_numsecflavors;
- for (i = 0; i < eap->ex_numsecflavors; i++)
- eap->ex_secflavors[i] = ep->ex_secflavors[i];
- if (eap->ex_numsecflavors == 0) {
+ ai = grp->gr_type == GT_HOST ? grp->gr_ptr.gt_addrinfo : NULL;
+ if (ep->ex_numsecflavors == 0) {
eap->ex_numsecflavors = 1;
eap->ex_secflavors[0] = AUTH_SYS;
- }
- done = FALSE;
-
- if (v4root_phase == 0) {
- build_iovec(&iov, &iovlen, "fstype", NULL, 0);
- build_iovec(&iov, &iovlen, "fspath", NULL, 0);
- build_iovec(&iov, &iovlen, "from", NULL, 0);
- build_iovec(&iov, &iovlen, "update", NULL, 0);
- build_iovec(&iov, &iovlen, "export", eap,
- sizeof (struct export_args));
- build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg));
+ } else {
+ eap->ex_numsecflavors = ep->ex_numsecflavors;
+ for (i = 0; i < eap->ex_numsecflavors; i++)
+ eap->ex_secflavors[i] = ep->ex_secflavors[i];
}
- while (!done) {
+ ret = 1;
+ for (;;) {
switch (grp->gr_type) {
case GT_HOST:
if (ai->ai_addr->sa_family == AF_INET6 && have_v6 == 0)
@@ -2398,13 +2398,14 @@ do_mount(struct exportlist *ep, struct g
if (grp->gr_ptr.gt_net.nt_net.ss_family == AF_INET6 &&
have_v6 == 0)
goto skip;
- eap->ex_addr =
- (struct sockaddr *)&grp->gr_ptr.gt_net.nt_net;
- eap->ex_addrlen =
- ((struct sockaddr
*)&grp->gr_ptr.gt_net.nt_net)->sa_len;
- eap->ex_mask =
- (struct sockaddr *)&grp->gr_ptr.gt_net.nt_mask;
- eap->ex_masklen = ((struct sockaddr
*)&grp->gr_ptr.gt_net.nt_mask)->sa_len;
+ eap->ex_addr = (struct sockaddr *)
+ &grp->gr_ptr.gt_net.nt_net;
+ eap->ex_addrlen = ((struct sockaddr *)
+ &grp->gr_ptr.gt_net.nt_net)->sa_len;
+ eap->ex_mask = (struct sockaddr *)
+ &grp->gr_ptr.gt_net.nt_mask;
+ eap->ex_masklen = ((struct sockaddr *)
+ &grp->gr_ptr.gt_net.nt_mask)->sa_len;
break;
case GT_DEFAULT:
eap->ex_addr = NULL;
@@ -2415,145 +2416,61 @@ do_mount(struct exportlist *ep, struct g
case GT_IGNORE:
ret = 0;
goto error_exit;
- break;
default:
syslog(LOG_ERR, "bad grouptype");
- if (cp)
- *cp = savedc;
- ret = 1;
goto error_exit;
- };
+ }
/*
- * For V4:, use the nfssvc() syscall, instead of mount().
+ * For V4:, use the nfssvc() syscall, instead of nmount().
*/
- if (v4root_phase == 2) {
- nfsea.fspec = v4root_dirpath;
- if (run_v4server > 0 &&
- nfssvc(NFSSVC_V4ROOTEXPORT, (caddr_t)&nfsea) < 0) {
- syslog(LOG_ERR, "Exporting V4: failed");
- return (2);
+ if (v4root_phase != 0) {
+ if (nfssvc(NFSSVC_V4ROOTEXPORT, &nfsea) < 0) {
+ syslog(LOG_ERR, "Exporting V4: failed: %m");
+ goto error_exit;
}
} else {
- /*
- * XXX:
- * Maybe I should just use the fsb->f_mntonname path
- * instead of looping back up the dirp to the mount
- * point??
- * Also, needs to know how to export all types of local
- * exportable filesystems and not just "ufs".
- */
- iov[1].iov_base = fsb->f_fstypename; /* "fstype" */
- iov[1].iov_len = strlen(fsb->f_fstypename) + 1;
- iov[3].iov_base = fsb->f_mntonname; /* "fspath" */
- iov[3].iov_len = strlen(fsb->f_mntonname) + 1;
- iov[5].iov_base = fsb->f_mntfromname; /* "from" */
- iov[5].iov_len = strlen(fsb->f_mntfromname) + 1;
-
- while (nmount(iov, iovlen, fsb->f_flags) < 0) {
- if (cp)
- *cp-- = savedc;
- else
- cp = dirp + dirplen - 1;
- if (opt_flags & OP_QUIET) {
- ret = 1;
- goto error_exit;
- }
- if (errno == EPERM) {
- if (debug)
- warnx("can't change attributes
for %s",
- dirp);
- syslog(LOG_ERR,
- "can't change attributes for %s",
- dirp);
- ret = 1;
- goto error_exit;
- }
- if (opt_flags & OP_ALLDIRS) {
- if (errno == EINVAL)
- syslog(LOG_ERR,
- "-alldirs requested but %s is not a filesystem mountpoint",
- dirp);
- else
- syslog(LOG_ERR,
- "could not remount %s: %m",
- dirp);
- ret = 1;
- goto error_exit;
- }
- /* back up over the last component */
- while (*cp == '/' && cp > dirp)
- cp--;
- while (*(cp - 1) != '/' && cp > dirp)
- cp--;
- if (cp == dirp) {
- if (debug)
- warnx("mnt unsucc");
- syslog(LOG_ERR, "can't export %s %s",
- dirp, errmsg);
- ret = 1;
- goto error_exit;
- }
- savedc = *cp;
- *cp = '\0';
- /*
- * Check that we're still on the same
- * filesystem.
- */
- if (statfs(dirp, &fsb1) != 0 ||
- bcmp(&fsb1.f_fsid, &fsb->f_fsid,
- sizeof (fsb1.f_fsid)) != 0) {
- *cp = savedc;
- syslog(LOG_ERR,
- "can't export %s %s", dirp,
- errmsg);
- ret = 1;
- goto error_exit;
- }
+ if (nmount(iov, iovlen, fsb->f_flags) < 0) {
+ ret = 1;
+ if (!(opt_flags & OP_QUIET))
+ syslog(LOG_ERR, "can't change "
+ "attributes for %s: %m", dirp);
+ goto error_exit;
}
}
-
- /*
- * For the experimental server:
- * If this is the public directory, get the file handle
- * and load it into the kernel via the nfssvc() syscall.
- */
- if (run_v4server > 0 && (exflags & MNT_EXPUBLIC) != 0) {
- fhandle_t fh;
- char *public_name;
-
- if (eap->ex_indexfile != NULL)
- public_name = eap->ex_indexfile;
- else
- public_name = dirp;
- if (getfh(public_name, &fh) < 0)
- syslog(LOG_ERR,
- "Can't get public fh for %s", public_name);
- else if (nfssvc(NFSSVC_PUBLICFH, (caddr_t)&fh) < 0)
- syslog(LOG_ERR,
- "Can't set public fh for %s", public_name);
- else
- has_publicfh = 1;
- }
skip:
if (ai != NULL)
ai = ai->ai_next;
if (ai == NULL)
- done = TRUE;
+ break;
+ }
+
+ /*
+ * For the experimental server:
+ * If this is the public directory, get the file handle
+ * and load it into the kernel via the nfssvc() syscall.
+ */
+ if (run_v4server > 0 && (exflags & MNT_EXPUBLIC)) {
+ fhandle_t fh;
+ const char *public_name;
+
+ public_name = eap->ex_indexfile != NULL ?
+ eap->ex_indexfile : dirp;
+ if (getfh(public_name, &fh) < 0)
+ syslog(LOG_ERR, "Can't get public fh for %s: %m",
+ public_name);
+ else if (nfssvc(NFSSVC_PUBLICFH, &fh) < 0)
+ syslog(LOG_ERR, "Can't set public fh for %s: %m",
+ public_name);
+ else
+ has_publicfh = 1;
}
- if (cp)
- *cp = savedc;
+ ret = 0;
error_exit:
- /* free strings allocated by strdup() in getmntopts.c */
+ /* Free data allocated by build_iovec(). */
if (iov != NULL) {
- free(iov[0].iov_base); /* fstype */
- free(iov[2].iov_base); /* fspath */
- free(iov[4].iov_base); /* from */
- free(iov[6].iov_base); /* update */
- free(iov[8].iov_base); /* export */
- free(iov[10].iov_base); /* errmsg */
-
- /* free iov, allocated by realloc() */
+ for (i = 0; i <= 10; i += 2)
+ free(iov[i].iov_base);
free(iov);
}
return (ret);
>Release-Note:
>Audit-Trail:
>Unformatted:
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