linux-kernel - Re: [PATCH] crash_core: optimize crash_exclude_mem

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: <20231229121014.fd090f8c616a34fbb45f7843@linux-foundation.org>
Date: Fri, 29 Dec 2023 12:10:14 -0800
From: Andrew Morton <akpm@...ux-foundation.org>
To: Yuntao Wang <ytcoode@...il.com>
Cc: bhe@...hat.com, bp@...en8.de, dave.hansen@...ux.intel.com,
 dyoung@...hat.com, hbathini@...ux.ibm.com, hpa@...or.com,
 kexec@...ts.infradead.org, linux-kernel@...r.kernel.org, mingo@...hat.com,
 seanjc@...gle.com, tglx@...utronix.de, tiwai@...e.de, vgoyal@...hat.com,
 x86@...nel.org
Subject: Re: [PATCH] crash_core: optimize crash_exclude_mem_range()

On Wed, 20 Dec 2023 00:34:18 +0800 Yuntao Wang <ytcoode@...il.com> wrote:

> Because memory ranges in mem->ranges are stored in ascending order, when we
> detect `p_end < start`, we can break the for loop early, as the subsequent
> memory ranges must also be outside the range we are looking for.
> 
> Signed-off-by: Yuntao Wang <ytcoode@...il.com>
> ---
> Hi Andrew,
> 
> Patch "[PATCH 2/2] crash_core: fix out-of-bounds access check in
> crash_exclude_mem_range()" can be ignored, use this patch instead.
> 

Some reviewer input on this would be helpful please?

> --- a/kernel/crash_core.c
> +++ b/kernel/crash_core.c
> @@ -575,9 +575,12 @@ int crash_exclude_mem_range(struct crash_mem *mem,
>  		p_start = mstart;
>  		p_end = mend;
>  
> -		if (p_start > end || p_end < start)
> +		if (p_start > end)
>  			continue;
>  
> +		if (p_end < start)
> +			break;
> +
>  		/* Truncate any area outside of range */
>  		if (p_start < start)
>  			p_start = start;
> -- 
> 2.43.0