Patch "ARM: 8731/1: Fix csum_partial_copy_from_user() stack mismatch" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

ARM: 8731/1: Fix csum_partial_copy_from_user() stack mismatch

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-8731-1-fix-csum_partial_copy_from_user-stack-mismatch.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 <[email protected]> know about it.

From: Chunyan Zhang <[email protected]>
Date: Fri, 1 Dec 2017 03:51:04 +0100
Subject: ARM: 8731/1: Fix csum_partial_copy_from_user() stack mismatch

From: Chunyan Zhang <[email protected]>

[ Upstream commit 36b0cb84ee858f02c256d26f0cb4229c78e3399e ]

An additional 'ip' will be pushed to the stack, for restoring the DACR later, if CONFIG_CPU_SW_DOMAIN_PAN defined.

However, the fixup still get the err_ptr by add #8*4 to sp, which results in the fact that the code area pointed by the LR will be overwritten, or the kernel will crash if CONFIG_DEBUG_RODATA is enabled.

This patch fixes the stack mismatch.

---
 arch/arm/lib/csumpartialcopyuser.S |    4 ++++
 1 file changed, 4 insertions(+)

@@ -85,7 +85,11 @@
 		.pushsection .text.fixup,"ax"
 		.align	4
 9001:		mov	r4, #-EFAULT
+#ifdef CONFIG_CPU_SW_DOMAIN_PAN
+		ldr	r5, [sp, #9*4]		@ *err_ptr
+#else
 		ldr	r5, [sp, #8*4]		@ *err_ptr
+#endif
 		str	r4, [r5]
 		ldmia	sp, {r1, r2}		@ retrieve dst, len
 		add	r2, r2, r1

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/arm-8731-1-fix-csum_partial_copy_from_user-stack-mismatch.patch