This is a note to let you know that I've just added the patch titled
arm: oabi compat: add missing access checks
to the 4.4-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-oabi-compat-add-missing-access-checks.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 7de249964f5578e67b99699c5f0b405738d820a2 Mon Sep 17 00:00:00 2001
From: Dave Weinstein <olorin@xxxxxxxxxx>
Date: Thu, 28 Jul 2016 11:55:41 -0700
Subject: arm: oabi compat: add missing access checks
From: Dave Weinstein <olorin@xxxxxxxxxx>
commit 7de249964f5578e67b99699c5f0b405738d820a2 upstream.
Add access checks to sys_oabi_epoll_wait() and sys_oabi_semtimedop().
This fixes CVE-2016-3857, a local privilege escalation under
CONFIG_OABI_COMPAT.
Reported-by: Chiachih Wu <wuchiachih@xxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Nicolas Pitre <nico@xxxxxxxxxx>
Signed-off-by: Dave Weinstein <olorin@xxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm/kernel/sys_oabi-compat.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
--- a/arch/arm/kernel/sys_oabi-compat.c
+++ b/arch/arm/kernel/sys_oabi-compat.c
@@ -279,8 +279,12 @@ asmlinkage long sys_oabi_epoll_wait(int
mm_segment_t fs;
long ret, err, i;
- if (maxevents <= 0 || maxevents > (INT_MAX/sizeof(struct epoll_event)))
+ if (maxevents <= 0 ||
+ maxevents > (INT_MAX/sizeof(*kbuf)) ||
+ maxevents > (INT_MAX/sizeof(*events)))
return -EINVAL;
+ if (!access_ok(VERIFY_WRITE, events, sizeof(*events) * maxevents))
+ return -EFAULT;
kbuf = kmalloc(sizeof(*kbuf) * maxevents, GFP_KERNEL);
if (!kbuf)
return -ENOMEM;
@@ -317,6 +321,8 @@ asmlinkage long sys_oabi_semtimedop(int
if (nsops < 1 || nsops > SEMOPM)
return -EINVAL;
+ if (!access_ok(VERIFY_READ, tsops, sizeof(*tsops) * nsops))
+ return -EFAULT;
sops = kmalloc(sizeof(*sops) * nsops, GFP_KERNEL);
if (!sops)
return -ENOMEM;
Patches currently in stable-queue which might be from olorin@xxxxxxxxxx are
queue-4.4/arm-oabi-compat-add-missing-access-checks.patch
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