linux-kernel - Re: [PATCH v2] perf: prevent overflow in size calculation

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: <5008C90A.50705@linux.vnet.ibm.com>
Date:	Thu, 19 Jul 2012 19:57:14 -0700
From:	Cody P Schafer <cody@...ux.vnet.ibm.com>
To:	Cody Schafer <cody@...ux.vnet.ibm.com>
CC:	Namhyung Kim <namhyung@...nel.org>,
	Arnaldo Carvalho de Melo <acme@...stprotocols.net>,
	Ingo Molnar <mingo@...hat.com>,
	Paul Mackerras <paulus@...ba.org>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Sukadev Bhattiprolu <sukadev@...ux.vnet.ibm.com>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2] perf: prevent overflow in size calculation


>   	struct annotation *notes = symbol__annotation(sym);
>   	const size_t size = symbol__size(sym);
> -	size_t sizeof_sym_hist = (sizeof(struct sym_hist) + size * sizeof(u64));
> +	size_t sizeof_sym_hist;
> +
> +	/* Check for overflow when calculating sizeof_sym_hist */
> +	if (size > (SIZE_MAX / sizeof(u64) - sizeof(struct sym_hist)))
> +		return -1;
> +
> +	sizeof_sym_hist = (sizeof(struct sym_hist) + size * sizeof(u64));
> +
> +	/* Check for overflow in zalloc argument */
> +	if (sizeof_sym_hist > (SIZE_MAX / symbol_conf.nr_events
> +				- sizeof(*notes->src)))
> +		return -1;
>
>   	notes->src = zalloc(sizeof(*notes->src) + symbol_conf.nr_events * sizeof_sym_hist);
>   	if (notes->src == NULL)
>

Actually, I don't think this is correct either (subtraction seems to 
occur in the wrong spot).

--
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/