diff options
| -rw-r--r-- | include/usage.h | 3 | ||||
| -rw-r--r-- | util-linux/mount.c | 73 |
2 files changed, 49 insertions, 27 deletions
diff --git a/include/usage.h b/include/usage.h index 0f6378e06..c6006aa65 100644 --- a/include/usage.h +++ b/include/usage.h @@ -2901,6 +2901,9 @@ "\n -f Dry run" \ ) \ ) \ + IF_FEATURE_MOUNT_HELPERS( \ + "\n -i Don't run mount helper" \ + ) \ IF_FEATURE_MTAB_SUPPORT( \ "\n -n Don't update /etc/mtab" \ ) \ 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; } } |