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Diffstat (limited to 'util-linux/mount.c')
-rw-r--r--util-linux/mount.c73
1 files changed, 46 insertions, 27 deletions
diff --git a/util-linux/mount.c b/util-linux/mount.c
index ab249642b..72dabd840 100644
--- a/util-linux/mount.c
+++ b/util-linux/mount.c
@@ -79,15 +79,21 @@ enum {
};
#if ENABLE_FEATURE_MTAB_SUPPORT
-#define useMtab (!(option_mask32 & OPT_n))
+#define USE_MTAB (!(option_mask32 & OPT_n))
#else
-#define useMtab 0
+#define USE_MTAB 0
#endif
#if ENABLE_FEATURE_MOUNT_FAKE
-#define fakeIt (option_mask32 & OPT_f)
+#define FAKE_IT (option_mask32 & OPT_f)
#else
-#define fakeIt 0
+#define FAKE_IT 0
+#endif
+
+#if ENABLE_FEATURE_MOUNT_HELPERS
+#define HELPERS_ALLOWED (!(option_mask32 & OPT_i))
+#else
+#define HELPERS_ALLOWED 0
#endif
@@ -360,7 +366,7 @@ static llist_t *get_block_backed_filesystems(void)
"/proc/filesystems",
};
char *fs, *buf;
- llist_t *list = 0;
+ llist_t *list = NULL;
int i;
FILE *f;
@@ -369,10 +375,11 @@ static llist_t *get_block_backed_filesystems(void)
if (!f) continue;
while ((buf = xmalloc_fgetline(f)) != NULL) {
- if (!strncmp(buf, "nodev", 5) && isspace(buf[5]))
+ if (strncmp(buf, "nodev", 5) == 0 && isspace(buf[5]))
continue;
fs = skip_whitespace(buf);
- if (*fs=='#' || *fs=='*' || !*fs) continue;
+ if (*fs == '#' || *fs == '*' || !*fs)
+ continue;
llist_add_to_end(&list, xstrdup(fs));
free(buf);
@@ -398,7 +405,7 @@ static int mount_it_now(struct mntent *mp, long vfsflags, char *filteropts)
{
int rc = 0;
- if (fakeIt) {
+ if (FAKE_IT) {
if (verbose >= 2)
bb_error_msg("would do mount('%s','%s','%s',0x%08lx,'%s')",
mp->mnt_fsname, mp->mnt_dir, mp->mnt_type,
@@ -414,11 +421,15 @@ static int mount_it_now(struct mntent *mp, long vfsflags, char *filteropts)
// If mount failed, try
// helper program mount.<mnt_type>
- if (ENABLE_FEATURE_MOUNT_HELPERS && rc) {
- char *args[6];
+ if (HELPERS_ALLOWED && rc) {
+ char *args[8];
int errno_save = errno;
args[0] = xasprintf("mount.%s", mp->mnt_type);
rc = 1;
+ if (FAKE_IT)
+ args[rc++] = (char *)"-f";
+ if (ENABLE_FEATURE_MTAB_SUPPORT && !USE_MTAB)
+ args[rc++] = (char *)"-n";
args[rc++] = mp->mnt_fsname;
args[rc++] = mp->mnt_dir;
if (filteropts) {
@@ -449,7 +460,7 @@ static int mount_it_now(struct mntent *mp, long vfsflags, char *filteropts)
// If the mount was successful, and we're maintaining an old-style
// mtab file by hand, add the new entry to it now.
mtab:
- if (useMtab && !rc && !(vfsflags & MS_REMOUNT)) {
+ if (USE_MTAB && !rc && !(vfsflags & MS_REMOUNT)) {
char *fsname;
FILE *mountTable = setmntent(bb_path_mtab_file, "a+");
const char *option_str = mount_option_str;
@@ -1570,8 +1581,8 @@ static int singlemount(struct mntent *mp, int ignore_busy)
{
int rc = -1;
long vfsflags;
- char *loopFile = 0, *filteropts = 0;
- llist_t *fl = 0;
+ char *loopFile = NULL, *filteropts = NULL;
+ llist_t *fl = NULL;
struct stat st;
vfsflags = parse_mount_options(mp->mnt_opts, &filteropts);
@@ -1581,21 +1592,28 @@ static int singlemount(struct mntent *mp, int ignore_busy)
mp->mnt_type = NULL;
// Might this be a virtual filesystem?
- if (ENABLE_FEATURE_MOUNT_HELPERS
- && (strchr(mp->mnt_fsname, '#'))
- ) {
- char *s, *p, *args[35];
- int n = 0;
-// FIXME: does it allow execution of arbitrary commands?!
-// What args[0] can end up with?
- for (s = p = mp->mnt_fsname; *s && n < 35-3; ++s) {
- if (s[0] == '#' && s[1] != '#') {
- *s = '\0';
- args[n++] = p;
- p = s + 1;
+ if (ENABLE_FEATURE_MOUNT_HELPERS && strchr(mp->mnt_fsname, '#')) {
+ char *args[35];
+ char *s;
+ int n;
+ // fsname: "cmd#arg1#arg2..."
+ // WARNING: allows execution of arbitrary commands!
+ // Try "mount 'sh#-c#sh' bogus_dir".
+ // It is safe ONLY because non-root
+ // cannot use two-argument mount command
+ // and using one-argument "mount 'sh#-c#sh'" doesn't work:
+ // "mount: can't find sh#-c#sh in /etc/fstab"
+ // (if /etc/fstab has it, it's ok: root sets up /etc/fstab).
+
+ s = mp->mnt_fsname;
+ n = 0;
+ args[n++] = s;
+ while (*s && n < 35 - 2) {
+ if (*s++ == '#' && *s != '#') {
+ s[-1] = '\0';
+ args[n++] = s;
}
}
- args[n++] = p;
args[n++] = mp->mnt_dir;
args[n] = NULL;
rc = wait4pid(xspawn(args));
@@ -1704,7 +1722,8 @@ static int singlemount(struct mntent *mp, int ignore_busy)
for (fl = fslist; fl; fl = fl->link) {
mp->mnt_type = fl->data;
rc = mount_it_now(mp, vfsflags, filteropts);
- if (!rc) break;
+ if (!rc)
+ break;
}
}