diff options
| author | Al Viro <viro@ftp.linux.org.uk> | 2007-10-07 00:24:36 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-07 16:28:43 -0700 |
| commit | 291041e935e6d0513f2b7e4a300aa9f02ec1d925 (patch) | |
| tree | 626b06b52d5ce0a41c7bf21ce4314e2a9fbe79ff /kernel/signal.c | |
| parent | 7a5c5d5735e785a700a377a5fce913b8ad45a58f (diff) | |
| download | lwn-291041e935e6d0513f2b7e4a300aa9f02ec1d925.tar.gz lwn-291041e935e6d0513f2b7e4a300aa9f02ec1d925.zip | |
fix bogus reporting of signals by audit
Async signals should not be reported as sent by current in audit log. As
it is, we call audit_signal_info() too early in check_kill_permission().
Note that check_kill_permission() has that test already - it needs to know
if it should apply current-based permission checks. So the solution is to
move the call of audit_signal_info() between those.
Bogosity in question is easily reproduced - add a rule watching for e.g.
kill(2) from specific process (so that audit_signal_info() would not
short-circuit to nothing), say load_policy, watch the bogus OBJ_PID entry
in audit logs claiming that write(2) on selinuxfs file issued by
load_policy(8) had somehow managed to send a signal to syslogd...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Steve Grubb <sgrubb@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 9fb91a32edda..792952381092 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -531,18 +531,18 @@ static int check_kill_permission(int sig, struct siginfo *info, if (!valid_signal(sig)) return error; - error = audit_signal_info(sig, t); /* Let audit system see the signal */ - if (error) - return error; - - error = -EPERM; - if ((info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info))) - && ((sig != SIGCONT) || - (process_session(current) != process_session(t))) - && (current->euid ^ t->suid) && (current->euid ^ t->uid) - && (current->uid ^ t->suid) && (current->uid ^ t->uid) - && !capable(CAP_KILL)) + if (info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info))) { + error = audit_signal_info(sig, t); /* Let audit system see the signal */ + if (error) + return error; + error = -EPERM; + if (((sig != SIGCONT) || + (process_session(current) != process_session(t))) + && (current->euid ^ t->suid) && (current->euid ^ t->uid) + && (current->uid ^ t->suid) && (current->uid ^ t->uid) + && !capable(CAP_KILL)) return error; + } return security_task_kill(t, info, sig, 0); } |