mount: fix bugs: free(mp->mnt_fsname) of non-malloced ptr;

check for "more than 2 arguments" was actually checking for -2.

1 files changed, 20 insertions, 17 deletions

diff --git a/util-linux/mount.c b/util-linux/mount.c
index 01b811471..ed81ba4b2 100644
--- a/util-linux/mount.c
+++ b/util-linux/mount.c
@@ -719,6 +719,7 @@ static void error_msg_rpc(const char *msg)
         bb_error_msg("%.*s", len, msg);
 }
 
+// NB: mp->xxx fields may be trashed on exit
 static int nfsmount(struct mntent *mp, int vfsflags, char *filteropts)
 {
         CLIENT *mclient;
@@ -1260,7 +1261,7 @@ int nfsmount(struct mntent *mp, int vfsflags, char *filteropts);
 
 // Mount one directory.  Handles CIFS, NFS, loopback, autobind, and filesystem
 // type detection.  Returns 0 for success, nonzero for failure.
-
+// NB: mp->xxx fields may be trashed on exit
 static int singlemount(struct mntent *mp, int ignore_busy)
 {
         int rc = -1, vfsflags;
@@ -1306,15 +1307,15 @@ static int singlemount(struct mntent *mp, int ignore_busy)
 
                 // compose new unc '\\server-ip\share'
 
-                s = xasprintf("\\\\%s%s",ip+3,strchr(mp->mnt_fsname+2,'\\'));
-                if (ENABLE_FEATURE_CLEAN_UP) free(mp->mnt_fsname);
-                mp->mnt_fsname = s;
+                mp->mnt_fsname = xasprintf("\\\\%s%s", ip+3,
+                                        strchr(mp->mnt_fsname+2,'\\'));
 
                 // lock is required
                 vfsflags |= MS_MANDLOCK;
 
                 mp->mnt_type = "cifs";
                 rc = mount_it_now(mp, vfsflags, filteropts);
+                if (ENABLE_FEATURE_CLEAN_UP) free(mp->mnt_fsname);
                 goto report_error;
         }
 
@@ -1457,14 +1458,16 @@ int mount_main(int argc, char **argv)
                                 bb_show_usage();
                 }
         }
+        argv += optind;
+        argc -= optind;
 
         // Three or more non-option arguments?  Die with a usage message.
 
-        if (optind-argc>2) bb_show_usage();
+        if (argc > 2) bb_show_usage();
 
         // If we have no arguments, show currently mounted filesystems
 
-        if (optind == argc) {
+        if (!argc) {
                 if (!all) {
                         FILE *mountTable = setmntent(bb_path_mtab_file, "r");
 
@@ -1484,15 +1487,15 @@ int mount_main(int argc, char **argv)
                         if (ENABLE_FEATURE_CLEAN_UP) endmntent(mountTable);
                         return EXIT_SUCCESS;
                 }
-        } else storage_path = bb_simplify_path(argv[optind]);
+        } else storage_path = bb_simplify_path(argv[0]);
 
         // When we have two arguments, the second is the directory and we can
         // skip looking at fstab entirely.  We can always abspath() the directory
         // argument when we get it.
 
-        if (optind+2 == argc) {
-                mtpair->mnt_fsname = argv[optind];
-                mtpair->mnt_dir = argv[optind+1];
+        if (argc == 2) {
+                mtpair->mnt_fsname = argv[0];
+                mtpair->mnt_dir = argv[1];
                 mtpair->mnt_type = fstype;
                 mtpair->mnt_opts = cmdopts;
                 rc = singlemount(mtpair, 0);
@@ -1504,8 +1507,8 @@ int mount_main(int argc, char **argv)
         if (ENABLE_FEATURE_MOUNT_FLAGS &&
                         (i & (MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE )))
         {
-                rc = mount("", argv[optind], "", i, "");
-                if (rc) bb_perror_msg_and_die("%s", argv[optind]);
+                rc = mount("", argv[0], "", i, "");
+                if (rc) bb_perror_msg_and_die("%s", argv[0]);
                 goto clean_up;
         }
         
@@ -1533,13 +1536,13 @@ int mount_main(int argc, char **argv)
                 {
                         // Were we looking for something specific?
 
-                        if (optind != argc) {
+                        if (argc) {
 
                                 // If we didn't find anything, complain.
 
                                 if (!mtnext->mnt_fsname)
                                         bb_error_msg_and_die("can't find %s in %s",
-                                                argv[optind], fstabname);
+                                                argv[0], fstabname);
 
                                 // Mount the last thing we found.
 
@@ -1556,13 +1559,13 @@ int mount_main(int argc, char **argv)
                  * skip it.  Note we must match both the exact text in fstab (ala
                  * "proc") or a full path from root */
 
-                if (optind != argc) {
+                if (argc) {
 
                         // Is this what we're looking for?
 
-                        if (strcmp(argv[optind],mtcur->mnt_fsname) &&
+                        if (strcmp(argv[0],mtcur->mnt_fsname) &&
                            strcmp(storage_path,mtcur->mnt_fsname) &&
-                           strcmp(argv[optind],mtcur->mnt_dir) &&
+                           strcmp(argv[0],mtcur->mnt_dir) &&
                            strcmp(storage_path,mtcur->mnt_dir)) continue;
 
                         // Remember this entry.  Something later may have overmounted