From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934333AbdA0Lcx (ORCPT ); Fri, 27 Jan 2017 06:32:53 -0500 Received: from mx2.suse.de ([195.135.220.15]:36795 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933671AbdA0LNK (ORCPT ); Fri, 27 Jan 2017 06:13:10 -0500 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Dave Martin , Catalin Marinas , Jiri Slaby Subject: [PATCH 3.12 191/235] arm64/ptrace: Reject attempts to set incomplete hardware breakpoint fields Date: Fri, 27 Jan 2017 11:55:24 +0100 Message-Id: X-Mailer: git-send-email 2.11.0 In-Reply-To: <5b46dc789ca2be4046e4e40a131858d386cac741.1485514374.git.jslaby@suse.cz> References: <5b46dc789ca2be4046e4e40a131858d386cac741.1485514374.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dave Martin 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit ad9e202aa1ce571b1d7fed969d06f66067f8a086 upstream. We cannot preserve partial fields for hardware breakpoints, because the values written by userspace to the hardware breakpoint registers can't subsequently be recovered intact from the hardware. So, just reject attempts to write incomplete fields with -EINVAL. Fixes: 478fcb2cdb23 ("arm64: Debugging support") Signed-off-by: Dave Martin Acked-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Jiri Slaby --- arch/arm64/kernel/ptrace.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 076bd41bf5ac..cdf1ec11c015 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -442,6 +442,8 @@ static int hw_break_set(struct task_struct *target, /* (address, ctrl) registers */ limit = regset->n * regset->size; while (count && offset < limit) { + if (count < PTRACE_HBP_ADDR_SZ) + return -EINVAL; ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr, offset, offset + PTRACE_HBP_ADDR_SZ); if (ret) @@ -451,6 +453,8 @@ static int hw_break_set(struct task_struct *target, return ret; offset += PTRACE_HBP_ADDR_SZ; + if (!count) + break; ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl, offset, offset + PTRACE_HBP_CTRL_SZ); if (ret) -- 2.11.0