This is a note to let you know that I've just added the patch titled
ARM: 7851/1: check for number of arguments in syscall_get/set_arguments()
to the 3.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm-7851-1-check-for-number-of-arguments-in-syscall_get-set_arguments.patch
and it can be found in the queue-3.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3c1532df5c1b54b5f6246cdef94eeb73a39fe43a Mon Sep 17 00:00:00 2001
From: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
Date: Wed, 9 Oct 2013 15:58:29 +0100
Subject: ARM: 7851/1: check for number of arguments in syscall_get/set_arguments()
From: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
commit 3c1532df5c1b54b5f6246cdef94eeb73a39fe43a upstream.
In ftrace_syscall_enter(),
syscall_get_arguments(..., 0, n, ...)
if (i == 0) { <handle ORIG_r0> ...; n--;}
memcpy(..., n * sizeof(args[0]));
If 'number of arguments(n)' is zero and 'argument index(i)' is also zero in
syscall_get_arguments(), none of arguments should be copied by memcpy().
Otherwise 'n--' can be a big positive number and unexpected amount of data
will be copied. Tracing system calls which take no argument, say sync(void),
may hit this case and eventually make the system corrupted.
This patch fixes the issue both in syscall_get_arguments() and
syscall_set_arguments().
Acked-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm/include/asm/syscall.h | 6 ++++++
1 file changed, 6 insertions(+)
--- a/arch/arm/include/asm/syscall.h
+++ b/arch/arm/include/asm/syscall.h
@@ -57,6 +57,9 @@ static inline void syscall_get_arguments
unsigned int i, unsigned int n,
unsigned long *args)
{
+ if (n == 0)
+ return;
+
if (i + n > SYSCALL_MAX_ARGS) {
unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i;
unsigned int n_bad = n + i - SYSCALL_MAX_ARGS;
@@ -81,6 +84,9 @@ static inline void syscall_set_arguments
unsigned int i, unsigned int n,
const unsigned long *args)
{
+ if (n == 0)
+ return;
+
if (i + n > SYSCALL_MAX_ARGS) {
pr_warning("%s called with max args %d, handling only %d\n",
__func__, i + n, SYSCALL_MAX_ARGS);
Patches currently in stable-queue which might be from takahiro.akashi@xxxxxxxxxx are
queue-3.11/arm-7851-1-check-for-number-of-arguments-in-syscall_get-set_arguments.patch
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