Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755207AbaFWNLX (ORCPT ); Mon, 23 Jun 2014 09:11:23 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:37170 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754801AbaFWNFL (ORCPT ); Mon, 23 Jun 2014 09:05:11 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Andrey Ryabinin , Linus Torvalds , Luis Henriques Subject: [PATCH 3.11 73/93] mm: rmap: fix use-after-free in __put_anon_vma Date: Mon, 23 Jun 2014 14:02:52 +0100 Message-Id: <1403528592-2163-74-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1403528592-2163-1-git-send-email-luis.henriques@canonical.com> References: <1403528592-2163-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.11.10.12 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrey Ryabinin commit 624483f3ea82598ab0f62f1bdb9177f531ab1892 upstream. While working address sanitizer for kernel I've discovered use-after-free bug in __put_anon_vma. For the last anon_vma, anon_vma->root freed before child anon_vma. Later in anon_vma_free(anon_vma) we are referencing to already freed anon_vma->root to check rwsem. This fixes it by freeing the child anon_vma before freeing anon_vma->root. Signed-off-by: Andrey Ryabinin Acked-by: Peter Zijlstra Signed-off-by: Linus Torvalds Signed-off-by: Luis Henriques --- mm/rmap.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/mm/rmap.c b/mm/rmap.c index 54935c5c9d60..f23ea5f31a31 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1684,10 +1684,9 @@ void __put_anon_vma(struct anon_vma *anon_vma) { struct anon_vma *root = anon_vma->root; + anon_vma_free(anon_vma); if (root != anon_vma && atomic_dec_and_test(&root->refcount)) anon_vma_free(root); - - anon_vma_free(anon_vma); } #ifdef CONFIG_MIGRATION -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/