diff options
| -rw-r--r-- | mount.cifs.c | 47 |
1 files changed, 38 insertions, 9 deletions
diff --git a/mount.cifs.c b/mount.cifs.c index f4aea01..aa5c9f9 100644 --- a/mount.cifs.c +++ b/mount.cifs.c @@ -267,10 +267,10 @@ static int set_password(struct parsed_mount_info *parsed_info, const char *src) } /* caller frees username if necessary */ -static char *getusername(void) +static char *getusername(uid_t uid) { char *username = NULL; - struct passwd *password = getpwuid(getuid()); + struct passwd *password = getpwuid(uid); if (password) username = password->pw_name; @@ -1054,9 +1054,39 @@ static int add_mtab(char *devname, char *mountpoint, unsigned long flags) { int rc = 0; - char *mount_user; + uid_t uid; + char *mount_user = NULL; struct mntent mountent; FILE *pmntfile; + sigset_t mask, oldmask; + + uid = getuid(); + if (uid != 0) + mount_user = getusername(uid); + + /* + * Set the real uid to the effective uid. This prevents unprivileged + * users from sending signals to this process, though ^c on controlling + * terminal should still work. + */ + rc = setreuid(geteuid(), -1); + if (rc != 0) { + fprintf(stderr, "Unable to set real uid to effective uid: %s\n", + strerror(errno)); + rc = EX_FILEIO; + } + + rc = sigfillset(&mask); + if (rc) { + fprintf(stderr, "Unable to set filled signal mask\n"); + return EX_FILEIO; + } + + rc = sigprocmask(SIG_SETMASK, &mask, &oldmask); + if (rc) { + fprintf(stderr, "Unable to make process ignore signals\n"); + return EX_FILEIO; + } atexit(unlock_mtab); rc = lock_mtab(); @@ -1094,12 +1124,10 @@ add_mtab(char *devname, char *mountpoint, unsigned long flags) strlcat(mountent.mnt_opts, ",nodev", MTAB_OPTIONS_LEN); if (flags & MS_SYNCHRONOUS) strlcat(mountent.mnt_opts, ",sync", MTAB_OPTIONS_LEN); - if (getuid() != 0) { + if (mount_user) { strlcat(mountent.mnt_opts, ",user=", MTAB_OPTIONS_LEN); - mount_user = getusername(); - if (mount_user) - strlcat(mountent.mnt_opts, mount_user, - MTAB_OPTIONS_LEN); + strlcat(mountent.mnt_opts, mount_user, + MTAB_OPTIONS_LEN); } } mountent.mnt_freq = 0; @@ -1109,6 +1137,7 @@ add_mtab(char *devname, char *mountpoint, unsigned long flags) unlock_mtab(); SAFE_FREE(mountent.mnt_opts); add_mtab_exit: + sigprocmask(SIG_SETMASK, &oldmask, NULL); if (rc) { fprintf(stderr, "unable to add mount entry to mtab\n"); rc = EX_FILEIO; @@ -1204,7 +1233,7 @@ assemble_mountinfo(struct parsed_mount_info *parsed_info, strlcpy(parsed_info->username, getenv("USER"), sizeof(parsed_info->username)); else - strlcpy(parsed_info->username, getusername(), + strlcpy(parsed_info->username, getusername(getuid()), sizeof(parsed_info->username)); parsed_info->got_user = 1; } |