Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753172AbcDRKtd (ORCPT ); Mon, 18 Apr 2016 06:49:33 -0400 Received: from mail.kernel.org ([198.145.29.136]:34663 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752122AbcDRKt3 (ORCPT ); Mon, 18 Apr 2016 06:49:29 -0400 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Vasant Hegde , Michael Ellerman , Zefan Li Subject: [PATCH 3.4 44/92] powerpc/rtas: Validate rtas.entry before calling enter_rtas() Date: Mon, 18 Apr 2016 18:45:49 +0800 Message-Id: <1460976397-5688-44-git-send-email-lizf@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1460976338-5631-1-git-send-email-lizf@kernel.org> References: <1460976338-5631-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1998 Lines: 54 From: Vasant Hegde 3.4.112-rc1 review patch. If anyone has any objections, please let me know. ------------------ 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: Zefan Li --- arch/powerpc/kernel/rtas.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c index b42cdc3..8178294 100644 --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -1042,6 +1042,9 @@ asmlinkage int ppc_rtas(struct rtas_args __user *uargs) if (!capable(CAP_SYS_ADMIN)) return -EPERM; + if (!rtas.entry) + return -EINVAL; + if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0) return -EFAULT; -- 1.9.1