Commit 241d2c54 authored Jul 02, 2015 by Andrey Ryabinin Committed by Ingo Molnar Jul 06, 2015

x86/kasan: Flush TLBs after switching CR3



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: <stable@vger.kernel.org> # 4.0+
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>

parent 5d5aa3cf

arch/x86/mm/kasan_init_64.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -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;
		}