From: Stephen Wilson <wilsons@start.ca>
To: Andrew Morton <akpm@linux-foundation.org>,
Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Michel Lespinasse <walken@google.com>,
Andi Kleen <ak@linux.intel.com>, Rik van Riel <riel@redhat.com>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
Matt Mackall <mpm@selenic.com>,
David Rientjes <rientjes@google.com>,
Nick Piggin <npiggin@kernel.dk>,
Andrea Arcangeli <aarcange@redhat.com>,
Mel Gorman <mel@csn.ul.ie>, Hugh Dickins <hughd@google.com>,
x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Stephen Wilson <wilsons@start.ca>
Subject: [PATCH 09/12] proc: disable mem_write after exec
Date: Sun, 13 Mar 2011 15:49:21 -0400 [thread overview]
Message-ID: <1300045764-24168-10-git-send-email-wilsons@start.ca> (raw)
In-Reply-To: <1300045764-24168-1-git-send-email-wilsons@start.ca>
This change makes mem_write() observe the same constraints as mem_read(). This
is particularly important for mem_write as an accidental leak of the fd across
an exec could result in arbitrary modification of the target process' memory.
IOW, /proc/pid/mem is implicitly close-on-exec.
Signed-off-by: Stephen Wilson <wilsons@start.ca>
---
fs/proc/base.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 9d096e8..e52702d 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -848,6 +848,10 @@ static ssize_t mem_write(struct file * file, const char __user *buf,
if (check_mem_permission(task))
goto out;
+ copied = -EIO;
+ if (file->private_data != (void *)((long)current->self_exec_id))
+ goto out;
+
copied = -ENOMEM;
page = (char *)__get_free_page(GFP_TEMPORARY);
if (!page)
--
1.7.3.5
--
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next prev parent reply other threads:[~2011-03-13 19:55 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-13 19:49 [PATCH v2 0/12] enable writing to /proc/pid/mem Stephen Wilson
2011-03-13 19:49 ` [PATCH 01/12] x86: add context tag to mark mm when running a task in 32-bit compatibility mode Stephen Wilson
2011-03-13 19:49 ` [PATCH 02/12] x86: mark associated mm when running a task in 32 bit " Stephen Wilson
2011-03-13 19:49 ` [PATCH 03/12] mm: arch: make get_gate_vma take an mm_struct instead of a task_struct Stephen Wilson
2011-03-13 19:49 ` [PATCH 04/12] mm: arch: make in_gate_area " Stephen Wilson
2011-03-13 19:49 ` [PATCH 05/12] mm: arch: rename in_gate_area_no_task to in_gate_area_no_mm Stephen Wilson
2011-03-13 19:49 ` [PATCH 06/12] mm: use mm_struct to resolve gate vma's in __get_user_pages Stephen Wilson
2011-03-13 19:49 ` [PATCH 07/12] mm: factor out main logic of access_process_vm Stephen Wilson
2011-03-13 19:49 ` [PATCH 08/12] mm: implement access_remote_vm Stephen Wilson
2011-03-13 19:49 ` Stephen Wilson [this message]
2011-03-13 19:49 ` [PATCH 10/12] proc: hold cred_guard_mutex in check_mem_permission() Stephen Wilson
2011-03-13 19:49 ` [PATCH 11/12] proc: make check_mem_permission() return an mm_struct on success Stephen Wilson
2011-03-14 0:08 ` Kees Cook
2011-03-14 0:59 ` Stephen Wilson
2011-03-14 15:13 ` Kees Cook
2011-03-13 19:49 ` [PATCH 12/12] proc: enable writing to /proc/pid/mem Stephen Wilson
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