From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752110AbdKVCUi (ORCPT ); Tue, 21 Nov 2017 21:20:38 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:56627 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751765AbdKVCUV (ORCPT ); Tue, 21 Nov 2017 21:20:21 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Oleg Nesterov" , "Linus Torvalds" , "Meelis Roos" Date: Wed, 22 Nov 2017 01:58:12 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 009/133] signal: move the "sig < SIGRTMIN" check into siginmask(sig) In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.51-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Oleg Nesterov commit 5c8ccefdf46c5f87d87b694c7fbc04941c2c99a5 upstream. All the users of siginmask() must ensure that sig < SIGRTMIN. sig_fatal() doesn't and this is wrong: UBSAN: Undefined behaviour in kernel/signal.c:911:6 shift exponent 32 is too large for 32-bit type 'long unsigned int' the patch doesn't add the neccesary check to sig_fatal(), it moves the check into siginmask() and updates other callers. Link: http://lkml.kernel.org/r/20160517195052.GA15187@redhat.com Reported-by: Meelis Roos Signed-off-by: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings --- include/linux/signal.h | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) --- a/include/linux/signal.h +++ b/include/linux/signal.h @@ -401,7 +401,9 @@ int unhandled_signal(struct task_struct #else #define rt_sigmask(sig) sigmask(sig) #endif -#define siginmask(sig, mask) (rt_sigmask(sig) & (mask)) + +#define siginmask(sig, mask) \ + ((sig) < SIGRTMIN && (rt_sigmask(sig) & (mask))) #define SIG_KERNEL_ONLY_MASK (\ rt_sigmask(SIGKILL) | rt_sigmask(SIGSTOP)) @@ -422,14 +424,10 @@ int unhandled_signal(struct task_struct rt_sigmask(SIGCONT) | rt_sigmask(SIGCHLD) | \ rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) ) -#define sig_kernel_only(sig) \ - (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_ONLY_MASK)) -#define sig_kernel_coredump(sig) \ - (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_COREDUMP_MASK)) -#define sig_kernel_ignore(sig) \ - (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_IGNORE_MASK)) -#define sig_kernel_stop(sig) \ - (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_STOP_MASK)) +#define sig_kernel_only(sig) siginmask(sig, SIG_KERNEL_ONLY_MASK) +#define sig_kernel_coredump(sig) siginmask(sig, SIG_KERNEL_COREDUMP_MASK) +#define sig_kernel_ignore(sig) siginmask(sig, SIG_KERNEL_IGNORE_MASK) +#define sig_kernel_stop(sig) siginmask(sig, SIG_KERNEL_STOP_MASK) #define sig_user_defined(t, signr) \ (((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) && \