Messages in this thread Patch in this message | | | From | Chunhui Li (李春辉) <> | Subject | 答复: [PATCH] kasan: avoid out-of-bounds in u nwind frame | Date | Wed, 10 Oct 2018 06:45:17 +0000 |
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Hi Mark,
kasan detect out-of-bounds in stacktrace.c line 70, it's already over READ_ONCE_NOCHECK, but still crash kernel-4.9/arch/arm64/kernel/stacktrace.c 69 frame->sp = fp + 0x10; 70 frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp));
we test on Android platform, kernel-4.9 build with clang 6.0.2, we will do experiment to clarify whether compiler related issue.
READ_ONCE_NOCHECK->__read_once_size_nocheck with __no_sanitize_address if enable CONFIG_KASAN
kernel-4.9/include/linux/compiler-gcc.h #define __no_sanitize_address __attribute__((no_sanitize_address))
kernel-4.9/include/linux/compiler-clang.h #define __no_sanitize_address __attribute__((no_sanitize("address")))
there is patch from internet, avoid kasan by wrapping with kasan_disable_current, it seems better. https://lore.kernel.org/patchwork/patch/644463 such as: + kasan_disable_current(); // access fp + kasan_enable_current();
Thanks Chunhui Li
-----邮件原件----- 发件人: Mark Rutland [mailto:mark.rutland@arm.com] 发送时间: 2018年10月9日 18:39 收件人: Chunhui Li (李春辉) 抄送: Catalin Marinas; Will Deacon; Matthias Brugger; Marc Zyngier; Ard Biesheuvel; James Morse; Masahiro Yamada; linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org; linux-mediatek@lists.infradead.org; wsd_upstream 主题: Re: [PATCH] kasan: avoid out-of-bounds in unwind_frame
On Tue, Oct 09, 2018 at 06:11:03PM +0800, Chunhui Li wrote: > From: "chunhui.li" <chunhui.li@mediatek.com> > > kasan detect unwind_frame out-of-bounds error when one task dump > another, log as below > BUG: KASAN: out-of-bounds in unwind_frame+0x140/0x20c Read of size 8 > at addr ffffffea1e2378e0 by task AnrMonitorThrea/1111 avoid kasan > out-of-bounds error by disable kasan for stacktrace.c
This doesn't look right. Since unwind_frame uses READ_ONCE_NOCHECK(), we should never perform an access that KASAN complains about.
I don't think that we should completely disable instrumentation of stacktrace.c.
Can you please figure out precisely which line KASAN is complaining about? i.e. use scripts/faddr2line.
Thanks, Mark.
> > Signed-off-by: chunhui.li <chunhui.li@mediatek.com> > --- > arch/arm64/kernel/Makefile | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile > index 95ac737..606d0e2 100644 > --- a/arch/arm64/kernel/Makefile > +++ b/arch/arm64/kernel/Makefile > @@ -57,6 +57,8 @@ arm64-obj-$(CONFIG_CRASH_DUMP) += crash_dump.o > arm64-obj-$(CONFIG_ARM_SDE_INTERFACE) += sdei.o > arm64-obj-$(CONFIG_ARM64_SSBD) += ssbd.o > > +KASAN_SANITIZE_stacktrace.o := n > + > obj-y += $(arm64-obj-y) vdso/ probes/ > obj-m += $(arm64-obj-m) > head-y := head.o > -- > 1.9.1 >
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