xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

signals: don't abuse __flush_signals() in selinux_bprm_committed_creds()

Browse Source 
selinux_bprm_committed_creds()->__flush_signals() is not right, we
shouldn't clear TIF_SIGPENDING unconditionally. There can be other
reasons for signal_pending(): freezing(), JOBCTL_PENDING_MASK, and
potentially more.

Also change this code to check fatal_signal_pending() rather than
SIGNAL_GROUP_EXIT, it looks a bit better.

Now we can kill __flush_signals() before it finds another buggy user.

Note: this code looks racy, we can flush a signal which was sent after
the task SID has been updated.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
This commit is contained in:
Oleg Nesterov
2015-06-04 16:22:16 -04:00
committed by Paul Moore
parent cded3fffbe
commit 9e7c8f8c62
3 changed files with 8 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
security/selinux/hooks.c
View File

@@ -2416,10 +2416,12 @@ static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
for (i = 0; i < 3; i++)
do_setitimer(i, &itimer, NULL);
spin_lock_irq(&current->sighand->siglock);
if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
__flush_signals(current);
if (!fatal_signal_pending(current)) {
flush_sigqueue(&current->pending);
flush_sigqueue(&current->signal->shared_pending);
flush_signal_handlers(current, 1);
sigemptyset(&current->blocked);
recalc_sigpending();
}
spin_unlock_irq(&current->sighand->siglock);
}