From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: Baruch Siach <baruch@tkos.co.il>
Cc: Ard Biesheuvel <ardb@kernel.org>, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] ARM: traps: print un-hashed user pc on undefined instruction
Date: Thu, 28 Jul 2022 16:23:17 +0100 [thread overview]
Message-ID: <YuKp5V815WT/WCG4@shell.armlinux.org.uk> (raw)
In-Reply-To: <515f8c621449e0f9aa7d11f998ce010676ba35fd.1658938681.git.baruch@tkos.co.il>
On Wed, Jul 27, 2022 at 07:18:01PM +0300, Baruch Siach wrote:
> When user undefined instruction debug is enabled pc value is hashed like
> kernel pointers for security reason. But the security benefit of this
> hash is very limited because the code goes on to call __show_regs() that
> prints the plain pointer value. pc is a user pointer anyway, so the
> kernel does not leak anything. The only result is confusion about the
> difference between the pc value on the first printed line, and the value
> that __show_regs() prints.
>
> Always print the plain value of pc.
>
> Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Looks sensible to me. Please drop it in the patch system, thanks.
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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prev parent reply other threads:[~2022-07-28 15:25 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-27 16:18 [PATCH] ARM: traps: print un-hashed user pc on undefined instruction Baruch Siach
2022-07-28 15:23 ` Russell King (Oracle) [this message]
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