[hackers] [ubase] mount: fix mount helper fs option handling || Brad Barden

From: <git_AT_suckless.org>
Date: Thu, 11 Feb 2016 11:16:47 +0100 (CET)

commit 4dbd00fc948efef8e8bbe4d52189e98701227948
Author: Brad Barden <b+suckless_AT_13os.net>
AuthorDate: Thu Jan 28 15:53:36 2016 -0600
Commit: sin <sin_AT_2f30.org>
CommitDate: Thu Feb 11 10:16:41 2016 +0000

    mount: fix mount helper fs option handling
    
    If a mount helper is used, only argopts (given on commandline) are
    passed to the helper via -o parameter. Option strings from fstab are
    ignored.
    
    This patch replaces global argopts pointer with a character array
    fsopts. A maximum length for filesytem options is #defined (used by
    fsopts and data), and argument/mntent options are length-checked to fit.
    A filesystem with too long an option string will print an error, cause
    mount to exit with an error status, and not attempt to mount the
    filesystem. This obviates the need for overflow checking of data in
    parseopts(), though it hasn't been removed.

diff --git a/mount.c b/mount.c
index 8888c60..2a7773e 100644
--- a/mount.c
+++ b/mount.c
_AT_@ -15,6 +15,8 @@
 #include "text.h"
 #include "util.h"
 
+#define FSOPTS_MAXLEN 512
+
 struct {
         const char *opt;
         const char *notopt;
_AT_@ -37,7 +39,7 @@ struct {
 };
 
 static unsigned long argflags = 0;
-static char *argopts = NULL;
+static char fsopts[FSOPTS_MAXLEN] = "";
 
 static char *
 findtype(const char *types, const char *t)
_AT_@ -121,9 +123,9 @@ mounthelper(const char *fsname, const char *dir, const char *fstype)
                 if (argflags & MS_REC)
                         eargv[i++] = "-R";
 
- if (argopts) {
+ if (fsopts[0]) {
                         eargv[i++] = "-o";
- eargv[i++] = argopts;
+ eargv[i++] = fsopts;
                 }
                 eargv[i++] = fsname;
                 eargv[i++] = dir;
_AT_@ -188,11 +190,11 @@ usage(void)
 int
 main(int argc, char *argv[])
 {
- char *types = NULL, data[512] = "", *resolvpath = NULL;
+ char *types = NULL, data[FSOPTS_MAXLEN] = "", *resolvpath = NULL;
         char *files[] = { "/proc/mounts", "/etc/fstab", NULL };
         const char *source, *target;
         struct mntent *me = NULL;
- int aflag = 0, oflag = 0, status = 0, i, r;
+ int aflag = 0, status = 0, i, r;
         unsigned long flags = 0;
         FILE *fp;
 
_AT_@ -210,9 +212,9 @@ main(int argc, char *argv[])
                 aflag = 1;
                 break;
         case 'o':
- oflag = 1;
- argopts = EARGF(usage());
- parseopts(argopts, &flags, data, sizeof(data));
+ if (strlcat(fsopts, EARGF(usage()), sizeof(fsopts)) >= sizeof(fsopts))
+ eprintf("option string too long\n");
+ parseopts(fsopts, &flags, data, sizeof(data));
                 break;
         case 't':
                 types = EARGF(usage());
_AT_@ -260,8 +262,10 @@ main(int argc, char *argv[])
                                         target = me->mnt_dir;
                                         source = me->mnt_fsname;
                                 }
- if (!oflag)
- parseopts(me->mnt_opts, &flags, data, sizeof(data));
+ if (!fsopts[0])
+ if (strlcat(fsopts, me->mnt_opts, sizeof(fsopts)) >= sizeof(fsopts))
+ eprintf("%s: option string too long\n", target);
+ parseopts(fsopts, &flags, data, sizeof(data));
                                 if (!types)
                                         types = me->mnt_type;
                                 goto mountsingle;
_AT_@ -294,7 +298,13 @@ mountall:
                 if (hasmntopt(me, MNTOPT_NOAUTO) || mounted(me->mnt_dir))
                         continue;
                 flags = 0;
- parseopts(me->mnt_opts, &flags, data, sizeof(data));
+ fsopts[0] = '\0';
+ if (strlcat(fsopts, me->mnt_opts, sizeof(fsopts)) >= sizeof(fsopts)) {
+ weprintf("%s: option string too long\n", me->mnt_dir);
+ status = 1;
+ continue;
+ }
+ parseopts(fsopts, &flags, data, sizeof(data));
                 /* if -t types specified:
                  * if non-match, skip
                  * if match and prefixed with "no", skip */
Received on Thu Feb 11 2016 - 11:16:47 CET