From: catalin.marinas@arm•com (Catalin Marinas)
To: linux-arm-kernel@lists•infradead.org
Subject: [Query] Stack Overflow in "arch/arm/kernel/unwind.c" while unwinding frame
Date: Wed, 2 Oct 2013 19:11:17 +0100 [thread overview]
Message-ID: <20131002181116.GH29794@arm.com> (raw)
In-Reply-To: <CAFrcx1m=3_74SiVecGF14DF827UzAwprNZMVVGRa46aqqVGATw@mail.gmail.com>
On 24 September 2013 07:23, Anurag Aggarwal <anurag19aggarwal@gmail•com> wrote:
> While executing unwind backtrace instructions in ARM, in the function
> unwind_exec_insn()
> there are chances that SP overflows from stack.
>
>
> For example while executing instruction with opcode 0xAE, vsp can go
> beyond stack to area that has not been allocated till now.
>
> unsigned long *vsp = (unsigned long *)ctrl->vrs[SP];
> int reg;
>
> /* pop R4-R[4+bbb] */
> for (reg = 4; reg <= 4 + (insn & 7); reg++)
> ctrl->vrs[reg] = *vsp++;
>
> The above scenario can happen while executing any of the unwind instruction.
>
> One of the ways to fix the problem is to check for vsp with stack
> limits before we increment it, but doing it for all the instructions
> seems a little bad.
>
> I just want to know that if anyone has faced the problem before
I haven't seen it but I think with some stack (or unwind bytecode)
corruption it could happen.
I think we could place some checks only when vsp is assigned and return
-URC_FAILURE, together with some warning.
--
Catalin
next prev parent reply other threads:[~2013-10-02 18:11 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAPoNrtuuMn=Bm9Mo=PsJfJp6DMQaM-Eaz5An+0+DXL2=uObndg@mail.gmail.com>
2013-09-24 6:28 ` [Query] Stack Overflow in "arch/arm/kernel/unwind.c" while unwinding frame Jean Pihet
2013-09-24 6:29 ` Anurag Aggarwal
2013-10-02 18:11 ` Catalin Marinas [this message]
2013-10-06 7:14 ` Anurag Aggarwal
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