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authorOleg Nesterov <oleg@redhat.com>2009-09-24 00:57:01 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-24 16:21:01 +0200
commit06f1631a1671bce2d59d58cb1debdf23e1803ebf (patch)
treed1c5cc02d8ceff4c50c098dce957ad63a09e84a5 /fs
parentsignals: introduce do_send_sig_info() helper (diff)
downloadlinux-06f1631a1671bce2d59d58cb1debdf23e1803ebf.tar.xz
linux-06f1631a1671bce2d59d58cb1debdf23e1803ebf.zip
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>
Diffstat (limited to 'fs')
-rw-r--r--fs/fcntl.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/fcntl.c b/fs/fcntl.c
index ae413086db97..50a988993262 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -461,11 +461,11 @@ static void send_sigio_to_task(struct task_struct *p,
else
si.si_band = band_table[reason - POLL_IN];
si.si_fd = fd;
- if (!group_send_sig_info(signum, &si, p))
+ if (!do_send_sig_info(signum, &si, p, true))
break;
/* fall-through: fall back on the old plain SIGIO signal */
case 0:
- group_send_sig_info(SIGIO, SEND_SIG_PRIV, p);
+ do_send_sig_info(SIGIO, SEND_SIG_PRIV, p, true);
}
}