| From 986d572418b1abec267571087f18b3433af47071 Mon Sep 17 00:00:00 2001 |
| From: Chris Morin <cmtm@google.com> |
| Date: Wed, 12 Dec 2018 19:59:27 -0800 |
| Subject: [PATCH] journal: support forwarding to syslog without CAP_SETUID and |
| CAP_SETGID |
| |
| Journald can forward messages to syslog when CAP_SYS_ADMIN is missing, |
| but not when CAP_SETUID or CAP_SETGID are missing. Prevent journald from |
| forging UNIX credentials at all when the first forwarding attempt fails. |
| This allows forwarding to work when journald has none of [CAP_SYS_ADMIN, |
| CAP_SETUID, CAP_SETGID]. |
| --- |
| src/journal/journald-syslog.c | 12 +++++------- |
| 1 file changed, 5 insertions(+), 7 deletions(-) |
| |
| diff --git a/src/journal/journald-syslog.c b/src/journal/journald-syslog.c |
| index a60a259bc4..e8b6915335 100644 |
| --- a/src/journal/journald-syslog.c |
| +++ b/src/journal/journald-syslog.c |
| @@ -75,15 +75,13 @@ static void forward_syslog_iovec(Server *s, const struct iovec *iovec, unsigned |
| } |
| |
| if (ucred && IN_SET(errno, ESRCH, EPERM)) { |
| - struct ucred u; |
| |
| - /* Hmm, presumably the sender process vanished |
| - * by now, or we don't have CAP_SYS_AMDIN, so |
| - * let's fix it as good as we can, and retry */ |
| + /* Hmm, presumably the sender process vanished by now, or we |
| + * don't have one of [CAP_SYS_AMDIN, CAP_SETUID, CAP_SETGID], |
| + * don't send any UNIX credentials */ |
| |
| - u = *ucred; |
| - u.pid = getpid_cached(); |
| - memcpy(CMSG_DATA(cmsg), &u, sizeof(struct ucred)); |
| + msghdr.msg_control = NULL; |
| + msghdr.msg_controllen = 0; |
| |
| if (sendmsg(s->syslog_fd, &msghdr, MSG_NOSIGNAL) >= 0) |
| return; |
| -- |
| 2.21.0.1020.gf2820cf01a-goog |
| |
