lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <556F5E86.3050102@redhat.com>
Date:	Wed, 03 Jun 2015 13:07:34 -0700
From:	Josh Stone <jistone@...hat.com>
To:	Russell King <rmk+kernel@....linux.org.uk>
CC:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Subject: Re: [PATCH 4.0 108/148] ARM: fix missing syscall trace exit

On 06/03/2015 05:09 AM, Greg Kroah-Hartman wrote:
> 4.0-stable review patch.  If anyone has any objections, please let me know.

I sent a copycat patch for arm64, but I think it may be a problem to
leave interrupts disabled for __sys_trace_return.  Thoughts, Russell?

> ------------------
> 
> From: Russell King <rmk+kernel@....linux.org.uk>
> 
> commit 1b97937246d8b97c0760d16d8992c7937bdf5e6a upstream.
> 
> Josh Stone reports:
> 
>   I've discovered a case where both arm and arm64 will miss a ptrace
>   syscall-exit that they should report.  If the syscall is entered
>   without TIF_SYSCALL_TRACE set, then it goes on the fast path.  It's
>   then possible to have TIF_SYSCALL_TRACE added in the middle of the
>   syscall, but ret_fast_syscall doesn't check this flag again.
> 
> Fix this by always checking for a syscall trace in the fast exit path.
> 
> Reported-by: Josh Stone <jistone@...hat.com>
> Signed-off-by: Russell King <rmk+kernel@....linux.org.uk>
> Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
> 
> ---
>  arch/arm/kernel/entry-common.S |    4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> --- a/arch/arm/kernel/entry-common.S
> +++ b/arch/arm/kernel/entry-common.S
> @@ -33,7 +33,9 @@ ret_fast_syscall:
>   UNWIND(.fnstart	)
>   UNWIND(.cantunwind	)
>  	disable_irq				@ disable interrupts
> -	ldr	r1, [tsk, #TI_FLAGS]
> +	ldr	r1, [tsk, #TI_FLAGS]		@ re-check for syscall tracing
> +	tst	r1, #_TIF_SYSCALL_WORK
> +	bne	__sys_trace_return
>  	tst	r1, #_TIF_WORK_MASK
>  	bne	fast_work_pending
>  	asm_trace_hardirqs_on
> 
> 

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ