From 32ed74a4b968a4faff7aaaff557035ce5d5e70ab Mon Sep 17 00:00:00 2001
From: Djalal Harouni <tixxdz@opendz.org>
Date: Mon, 7 Apr 2014 15:38:38 -0700
Subject: [PATCH] procfs: make /proc/*/pagemap 0400
The /proc/*/pagemap contain sensitive information and currently its mode
is 0444. Change this to 0400, so the VFS will prevent unprivileged
processes from getting file descriptors on arbitrary privileged
/proc/*/pagemap files.
This reduces the scope of address space leaking and bypasses by protecting
already running processes.
Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/proc/base.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index a08c922893571..8da60e768b42f 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2617,7 +2617,7 @@ static const struct pid_entry tgid_base_stuff[] = {
#ifdef CONFIG_PROC_PAGE_MONITOR
REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
REG("smaps", S_IRUGO, proc_pid_smaps_operations),
- REG("pagemap", S_IRUGO, proc_pagemap_operations),
+ REG("pagemap", S_IRUSR, proc_pagemap_operations),
#endif
#ifdef CONFIG_SECURITY
DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
@@ -2955,7 +2955,7 @@ static const struct pid_entry tid_base_stuff[] = {
#ifdef CONFIG_PROC_PAGE_MONITOR
REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
REG("smaps", S_IRUGO, proc_tid_smaps_operations),
- REG("pagemap", S_IRUGO, proc_pagemap_operations),
+ REG("pagemap", S_IRUSR, proc_pagemap_operations),
#endif
#ifdef CONFIG_SECURITY
DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
--
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