linux-kernel - Re: [PATCH v2] nvmem/mxs-ocotp: fix buffer overflow in read

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: <57275C69.9060902@i2se.com>
Date:	Mon, 2 May 2016 15:55:53 +0200
From:	Stefan Wahren <stefan.wahren@...e.com>
To:	Srinivas Kandagatla <srinivas.kandagatla@...aro.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:	Stanislav Meduna <stano@...una.org>, linux-kernel@...r.kernel.org,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	Maxime Ripard <maxime.ripard@...e-electrons.com>
Subject: Re: [PATCH v2] nvmem/mxs-ocotp: fix buffer overflow in read

Hi Srinivas,
hi Greg,

Am 27.04.2016 um 14:39 schrieb Stanislav Meduna:
> This patch fixes the issue where the mxs_ocotp_read is reading
> the ocotp in reg_size steps but decrements the remaining size
> by 1. The number of iterations is thus four times higher,
> overwriting the area behind the output buffer.
>
> Fixes: c01e9a11ab6f ("nvmem: add driver for ocotp in i.MX23 and i.MX28")
> Tested-by: Stefan Wahren <stefan.wahren@...e.com>
> Signed-off-by: Stanislav Meduna <stano@...una.org>

any change to get this critical fix into 4.6?

Regards
Stefan

> ---
>  drivers/nvmem/mxs-ocotp.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/nvmem/mxs-ocotp.c b/drivers/nvmem/mxs-ocotp.c
> index 8ba19bb..2bb3c57 100644
> --- a/drivers/nvmem/mxs-ocotp.c
> +++ b/drivers/nvmem/mxs-ocotp.c
> @@ -94,7 +94,7 @@ static int mxs_ocotp_read(void *context, const void *reg, size_t reg_size,
>  	if (ret)
>  		goto close_banks;
>
> -	while (val_size) {
> +	while (val_size >= reg_size) {
>  		if ((offset < OCOTP_DATA_OFFSET) || (offset % 16)) {
>  			/* fill up non-data register */
>  			*buf = 0;
> @@ -103,7 +103,7 @@ static int mxs_ocotp_read(void *context, const void *reg, size_t reg_size,
>  		}
>
>  		buf++;
> -		val_size--;
> +		val_size -= reg_size;
>  		offset += reg_size;
>  	}
>