tree d1c5cc02d8ceff4c50c098dce957ad63a09e84a5
parent 4a30debfb778240a4b1767d4b0c5a5b25ab97160
author Oleg Nesterov <oleg@redhat.com> 1253746621 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1253802061 -0700

signals: send_sigio: use do_send_sig_info() to avoid check_kill_permission()

group_send_sig_info()->check_kill_permission() assumes that current is the
sender and uses current_cred().

This is not true in send_sigio_to_task() case.  From the security pov the
sender is not current, but the task which did fcntl(F_SETOWN), that is why
we have sigio_perm() which uses the right creds to check.

Fortunately, send_sigio() always sends either SEND_SIG_PRIV or
SI_FROMKERNEL() signal, so check_kill_permission() does nothing.  But
still it would be tidier to avoid this bogus security check and save a
couple of cycles.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stephane eranian <eranian@googlemail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>