| author | Jonathan Liu <net147@gmail.com> | 2013-05-21 15:01:55 (GMT) |
|---|---|---|
| committer | Denys Vlasenko <vda.linux@googlemail.com> | 2013-05-21 15:01:55 (GMT) |
| commit | b6dc13c2d3754704b1bf5af4e6b957b48585102f (patch) | |
| tree | fd04dfd6847a6e194fa92676fd2fec8574567dba | |
| parent | 9cb1e2f86b08da469bb4680cf68e927534b5a2ab (diff) | |
| download | busybox-b6dc13c2d3754704b1bf5af4e6b957b48585102f.zip busybox-b6dc13c2d3754704b1bf5af4e6b957b48585102f.tar.gz busybox-b6dc13c2d3754704b1bf5af4e6b957b48585102f.tar.bz2 | |
sulogin: allow system maintenance login if root password is empty
The current password checking is unable to distinguish between the user
entering an empty password or pressing Control-D. As a result, an empty
password always results in normal startup.
We modify bb_ask to return NULL if Control-D is pressed without entering
a password. The sulogin applet is then modified to only proceed to
normal startup if bb_ask returns NULL. This covers EOF with no password,
interrupt by timeout and ^C.
Signed-off-by: Jonathan Liu <net147@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
| -rw-r--r-- | libbb/bb_askpass.c | 4 | ||||
| -rw-r--r-- | loginutils/sulogin.c | 4 |
2 files changed, 5 insertions, 3 deletions
diff --git a/libbb/bb_askpass.c b/libbb/bb_askpass.c index fe2b506..77c1bcd 100644 --- a/libbb/bb_askpass.c +++ b/libbb/bb_askpass.c @@ -65,7 +65,9 @@ char* FAST_FUNC bb_ask(const int fd, int timeout, const char *prompt) i = 0; while (1) { int r = read(fd, &ret[i], 1); - if (r < 0) { + if ((i == 0 && r == 0) /* EOF (^D) with no password */ + || r < 0 + ) { /* read is interrupted by timeout or ^C */ ret = NULL; break; diff --git a/loginutils/sulogin.c b/loginutils/sulogin.c index f79802a..65e6384 100644 --- a/loginutils/sulogin.c +++ b/loginutils/sulogin.c @@ -83,8 +83,8 @@ int sulogin_main(int argc UNUSED_PARAM, char **argv) cp = bb_ask(STDIN_FILENO, timeout, "Give root password for system maintenance\n" "(or type Control-D for normal startup):"); - - if (!cp || !*cp) { + if (!cp) { + /* ^D, ^C, timeout, or read error */ bb_info_msg("Normal startup"); return 0; } |