From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933321AbcI2JHT (ORCPT ); Thu, 29 Sep 2016 05:07:19 -0400 Received: from mx2.suse.de ([195.135.220.15]:39909 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932731AbcI2JHI (ORCPT ); Thu, 29 Sep 2016 05:07:08 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: Vineet Gupta , Linus Torvalds , linux-snps-arc@lists.infradead.org, linux-kernel@vger.kernel.org, Vineet Gupta , Al Viro , Jiri Slaby Subject: [patch added to 3.12-stable] ARC: uaccess: get_user to zero out dest in cause of fault Date: Thu, 29 Sep 2016 11:06:35 +0200 Message-Id: <20160929090654.27405-24-jslaby@suse.cz> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20160929090654.27405-1-jslaby@suse.cz> References: <20160929090654.27405-1-jslaby@suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vineet Gupta This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== commit 05d9d0b96e53c52a113fd783c0c97c830c8dc7af upstream. Al reported potential issue with ARC get_user() as it wasn't clearing out destination pointer in case of fault due to bad address etc. Verified using following | { | u32 bogus1 = 0xdeadbeef; | u64 bogus2 = 0xdead; | int rc1, rc2; | | pr_info("Orig values %x %llx\n", bogus1, bogus2); | rc1 = get_user(bogus1, (u32 __user *)0x40000000); | rc2 = get_user(bogus2, (u64 __user *)0x50000000); | pr_info("access %d %d, new values %x %llx\n", | rc1, rc2, bogus1, bogus2); | } | [ARCLinux]# insmod /mnt/kernel-module/qtn.ko | Orig values deadbeef dead | access -14 -14, new values 0 0 Reported-by: Al Viro Cc: Linus Torvalds Cc: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Vineet Gupta Signed-off-by: Al Viro Signed-off-by: Jiri Slaby --- arch/arc/include/asm/uaccess.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/arc/include/asm/uaccess.h b/arch/arc/include/asm/uaccess.h index 30c9baffa96f..08770c750696 100644 --- a/arch/arc/include/asm/uaccess.h +++ b/arch/arc/include/asm/uaccess.h @@ -83,7 +83,10 @@ "2: ;nop\n" \ " .section .fixup, \"ax\"\n" \ " .align 4\n" \ - "3: mov %0, %3\n" \ + "3: # return -EFAULT\n" \ + " mov %0, %3\n" \ + " # zero out dst ptr\n" \ + " mov %1, 0\n" \ " j 2b\n" \ " .previous\n" \ " .section __ex_table, \"a\"\n" \ @@ -101,7 +104,11 @@ "2: ;nop\n" \ " .section .fixup, \"ax\"\n" \ " .align 4\n" \ - "3: mov %0, %3\n" \ + "3: # return -EFAULT\n" \ + " mov %0, %3\n" \ + " # zero out dst ptr\n" \ + " mov %1, 0\n" \ + " mov %R1, 0\n" \ " j 2b\n" \ " .previous\n" \ " .section __ex_table, \"a\"\n" \ -- 2.10.0 From mboxrd@z Thu Jan 1 00:00:00 1970 From: jslaby@suse.cz (Jiri Slaby) Date: Thu, 29 Sep 2016 11:06:35 +0200 Subject: [patch added to 3.12-stable] ARC: uaccess: get_user to zero out dest in cause of fault In-Reply-To: <20160929090654.27405-1-jslaby@suse.cz> References: <20160929090654.27405-1-jslaby@suse.cz> List-ID: Message-ID: <20160929090654.27405-24-jslaby@suse.cz> To: linux-snps-arc@lists.infradead.org From: Vineet Gupta This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== commit 05d9d0b96e53c52a113fd783c0c97c830c8dc7af upstream. Al reported potential issue with ARC get_user() as it wasn't clearing out destination pointer in case of fault due to bad address etc. Verified using following | { | u32 bogus1 = 0xdeadbeef; | u64 bogus2 = 0xdead; | int rc1, rc2; | | pr_info("Orig values %x %llx\n", bogus1, bogus2); | rc1 = get_user(bogus1, (u32 __user *)0x40000000); | rc2 = get_user(bogus2, (u64 __user *)0x50000000); | pr_info("access %d %d, new values %x %llx\n", | rc1, rc2, bogus1, bogus2); | } | [ARCLinux]# insmod /mnt/kernel-module/qtn.ko | Orig values deadbeef dead | access -14 -14, new values 0 0 Reported-by: Al Viro Cc: Linus Torvalds Cc: linux-snps-arc at lists.infradead.org Cc: linux-kernel at vger.kernel.org Signed-off-by: Vineet Gupta Signed-off-by: Al Viro Signed-off-by: Jiri Slaby --- arch/arc/include/asm/uaccess.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/arc/include/asm/uaccess.h b/arch/arc/include/asm/uaccess.h index 30c9baffa96f..08770c750696 100644 --- a/arch/arc/include/asm/uaccess.h +++ b/arch/arc/include/asm/uaccess.h @@ -83,7 +83,10 @@ "2: ;nop\n" \ " .section .fixup, \"ax\"\n" \ " .align 4\n" \ - "3: mov %0, %3\n" \ + "3: # return -EFAULT\n" \ + " mov %0, %3\n" \ + " # zero out dst ptr\n" \ + " mov %1, 0\n" \ " j 2b\n" \ " .previous\n" \ " .section __ex_table, \"a\"\n" \ @@ -101,7 +104,11 @@ "2: ;nop\n" \ " .section .fixup, \"ax\"\n" \ " .align 4\n" \ - "3: mov %0, %3\n" \ + "3: # return -EFAULT\n" \ + " mov %0, %3\n" \ + " # zero out dst ptr\n" \ + " mov %1, 0\n" \ + " mov %R1, 0\n" \ " j 2b\n" \ " .previous\n" \ " .section __ex_table, \"a\"\n" \ -- 2.10.0