From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753547AbbKOCIg (ORCPT ); Sat, 14 Nov 2015 21:08:36 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35301 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752292AbbKOCEw (ORCPT ); Sat, 14 Nov 2015 21:04:52 -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, "NAGESWARA R. SASTRY" , "Michael Ellerman" , "Vasant Hegde" Date: Sun, 15 Nov 2015 01:45:45 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 40/60] powerpc/rtas: Validate rtas.entry before calling enter_rtas() In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.247 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 3.2.73-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Vasant Hegde commit 8832317f662c06f5c06e638f57bfe89a71c9b266 upstream. Currently we do not validate rtas.entry before calling enter_rtas(). This leads to a kernel oops when user space calls rtas system call on a powernv platform (see below). This patch adds code to validate rtas.entry before making enter_rtas() call. Oops: Exception in kernel mode, sig: 4 [#1] SMP NR_CPUS=1024 NUMA PowerNV task: c000000004294b80 ti: c0000007e1a78000 task.ti: c0000007e1a78000 NIP: 0000000000000000 LR: 0000000000009c14 CTR: c000000000423140 REGS: c0000007e1a7b920 TRAP: 0e40 Not tainted (3.18.17-340.el7_1.pkvm3_1_0.2400.1.ppc64le) MSR: 1000000000081000 CR: 00000000 XER: 00000000 CFAR: c000000000009c0c SOFTE: 0 NIP [0000000000000000] (null) LR [0000000000009c14] 0x9c14 Call Trace: [c0000007e1a7bba0] [c00000000041a7f4] avc_has_perm_noaudit+0x54/0x110 (unreliable) [c0000007e1a7bd80] [c00000000002ddc0] ppc_rtas+0x150/0x2d0 [c0000007e1a7be30] [c000000000009358] syscall_exit+0x0/0x98 Fixes: 55190f88789a ("powerpc: Add skeleton PowerNV platform") Reported-by: NAGESWARA R. SASTRY Signed-off-by: Vasant Hegde [mpe: Reword change log, trim oops, and add stable + fixes] Signed-off-by: Michael Ellerman Signed-off-by: Ben Hutchings --- arch/powerpc/kernel/rtas.c | 3 +++ 1 file changed, 3 insertions(+) --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -992,6 +992,9 @@ asmlinkage int ppc_rtas(struct rtas_args if (!capable(CAP_SYS_ADMIN)) return -EPERM; + if (!rtas.entry) + return -EINVAL; + if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0) return -EFAULT;