diff options
| author | Theo de Raadt <deraadt@cvs.openbsd.org> | 2024-06-26 23:16:53 +0000 |
|---|---|---|
| committer | Theo de Raadt <deraadt@cvs.openbsd.org> | 2024-06-26 23:16:53 +0000 |
| commit | 72dd8e318fb1f7f563d56a7658ec8d8d954dc78a (patch) | |
| tree | 223f47260ace6cad442a736a54506e1d545ca9b1 /usr.bin/ssh | |
| parent | 4e77a5592007b61d7f13df44a0630cc68dca07ca (diff) | |
Instead of using possibly complex ssh_signal(), write all the parts
of the grace_alarm_handler() using the exact things allowed by the
signal-safe rules. This is a good rule of thumb: Handlers should
be written to either set a global volatile sig_atomic_t inspected
from outside, and/or directly perform only safe operations listed
in our sigaction(2) manual page.
ok djm markus
Diffstat (limited to 'usr.bin/ssh')
| -rw-r--r-- | usr.bin/ssh/sshd-session.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/usr.bin/ssh/sshd-session.c b/usr.bin/ssh/sshd-session.c index e75b4f80bca..54b7a8f71e6 100644 --- a/usr.bin/ssh/sshd-session.c +++ b/usr.bin/ssh/sshd-session.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sshd-session.c,v 1.3 2024/06/06 17:15:25 djm Exp $ */ +/* $OpenBSD: sshd-session.c,v 1.4 2024/06/26 23:16:52 deraadt Exp $ */ /* * SSH2 implementation: * Privilege Separation: @@ -176,6 +176,8 @@ static void do_ssh2_kex(struct ssh *); /* * Signal handler for the alarm after the login grace period has expired. + * As usual, this may only take signal-safe actions, even though it is + * terminal. */ static void grace_alarm_handler(int sig) @@ -185,7 +187,14 @@ grace_alarm_handler(int sig) * keys command helpers or privsep children. */ if (getpgid(0) == getpid()) { - ssh_signal(SIGTERM, SIG_IGN); + struct sigaction sa; + + /* mask all other signals while in handler */ + memset(&sa, 0, sizeof(sa)); + sa.sa_handler = SIG_IGN; + sigfillset(&sa.sa_mask); + sa.sa_flags = SA_RESTART; + (void)sigaction(SIGTERM, &sa, NULL); kill(0, SIGTERM); } _exit(EXIT_LOGIN_GRACE); |