From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753175AbaDAQjv (ORCPT ); Tue, 1 Apr 2014 12:39:51 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:44414 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752283AbaDAQJe (ORCPT ); Tue, 1 Apr 2014 12:09:34 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Artem Fetishev , Aleksandr Terekhov , Andrew Morton , Linus Torvalds , Kamal Mostafa Subject: [PATCH 3.8 67/86] fs/proc/base.c: fix GPF in /proc/$PID/map_files Date: Tue, 1 Apr 2014 09:08:20 -0700 Message-Id: <1396368519-12728-68-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1396368519-12728-1-git-send-email-kamal@canonical.com> References: <1396368519-12728-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.8.13.21 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Artem Fetishev commit 70335abb2689c8cd5df91bf2d95a65649addf50b upstream. The expected logic of proc_map_files_get_link() is either to return 0 and initialize 'path' or return an error and leave 'path' uninitialized. By the time dname_to_vma_addr() returns 0 the corresponding vma may have already be gone. In this case the path is not initialized but the return value is still 0. This results in 'general protection fault' inside d_path(). Steps to reproduce: CONFIG_CHECKPOINT_RESTORE=y fd = open(...); while (1) { mmap(fd, ...); munmap(fd, ...); } ls -la /proc/$PID/map_files Addresses https://bugzilla.kernel.org/show_bug.cgi?id=68991 Signed-off-by: Artem Fetishev Signed-off-by: Aleksandr Terekhov Reported-by: Acked-by: Pavel Emelyanov Acked-by: Cyrill Gorcunov Reviewed-by: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Kamal Mostafa --- fs/proc/base.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/proc/base.c b/fs/proc/base.c index 9b43ff77..78150a0 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1784,6 +1784,7 @@ static int proc_map_files_get_link(struct dentry *dentry, struct path *path) if (rc) goto out_mmput; + rc = -ENOENT; down_read(&mm->mmap_sem); vma = find_exact_vma(mm, vm_start, vm_end); if (vma && vma->vm_file) { -- 1.8.3.2