Patch "x86/kasan: Flush TLBs after switching CR3" has been added to the 4.1-stable tree

Patch "x86/kasan: Flush TLBs after switching CR3" has been added to the 4.1-stable tree

[gregkh]

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

    x86/kasan: Flush TLBs after switching CR3

to the 4.1-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:
     x86-kasan-flush-tlbs-after-switching-cr3.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 241d2c54c62fa0939fc9a9512b48ac3434e90a89 Mon Sep 17 00:00:00 2001
From: Andrey Ryabinin <a.ryabinin@samsung.com>
Date: Thu, 2 Jul 2015 12:09:35 +0300
Subject: x86/kasan: Flush TLBs after switching CR3

From: Andrey Ryabinin <a.ryabinin@samsung.com>

commit 241d2c54c62fa0939fc9a9512b48ac3434e90a89 upstream.

load_cr3() doesn't cause tlb_flush if PGE enabled.

This may cause tons of false positive reports spamming the
kernel to death.

To fix this __flush_tlb_all() should be called explicitly
after CR3 changed.

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Alexander Popov <alpopov@ptsecurity.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1435828178-10975-4-git-send-email-a.ryabinin@samsung.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/mm/kasan_init_64.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/arch/x86/mm/kasan_init_64.c
+++ b/arch/x86/mm/kasan_init_64.c
@@ -208,6 +208,7 @@ void __init kasan_init(void)
 
 	memcpy(early_level4_pgt, init_level4_pgt, sizeof(early_level4_pgt));
 	load_cr3(early_level4_pgt);
+	__flush_tlb_all();
 
 	clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END);
 
@@ -234,5 +235,6 @@ void __init kasan_init(void)
 	memset(kasan_zero_page, 0, PAGE_SIZE);
 
 	load_cr3(init_level4_pgt);
+	__flush_tlb_all();
 	init_task.kasan_depth = 0;
 }


Patches currently in stable-queue which might be from a.ryabinin@samsung.com are

queue-4.1/x86-kasan-fix-kasan-shadow-region-page-tables.patch
queue-4.1/x86-kasan-fix-boot-crash-on-amd-processors.patch
queue-4.1/x86-init-clear-init_level4_pgt-earlier.patch
queue-4.1/x86-kasan-flush-tlbs-after-switching-cr3.patch