netdev - RE: [PATCH] ar5523: check NULL before memcpy() in ar5523

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]

Date:   Mon, 30 Sep 2019 15:35:42 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     'Denis Efremov' <efremov@...ux.com>,
        "linux-wireless@...r.kernel.org" <linux-wireless@...r.kernel.org>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:     Pontus Fuchs <pontus.fuchs@...il.com>,
        Kalle Valo <kvalo@...eaurora.org>,
        "David S. Miller" <davem@...emloft.net>,
        "stable@...r.kernel.org" <stable@...r.kernel.org>
Subject: RE: [PATCH] ar5523: check NULL before memcpy() in ar5523_cmd()

From: Denis Efremov
> Sent: 30 September 2019 15:02
> 
> memcpy() call with "idata == NULL && ilen == 0" results in undefined
> behavior in ar5523_cmd(). For example, NULL is passed in callchain
> "ar5523_stat_work() -> ar5523_cmd_write() -> ar5523_cmd()". This patch
> adds idata check before memcpy() call in ar5523_cmd() to prevent an
> undefined behavior.
> 
...
> Signed-off-by: Denis Efremov <efremov@...ux.com>
> ---
>  drivers/net/wireless/ath/ar5523/ar5523.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/ath/ar5523/ar5523.c b/drivers/net/wireless/ath/ar5523/ar5523.c
> index b94759daeacc..f25af5bc5282 100644
> --- a/drivers/net/wireless/ath/ar5523/ar5523.c
> +++ b/drivers/net/wireless/ath/ar5523/ar5523.c
> @@ -255,7 +255,8 @@ static int ar5523_cmd(struct ar5523 *ar, u32 code, const void *idata,
> 
>  	if (flags & AR5523_CMD_FLAG_MAGIC)
>  		hdr->magic = cpu_to_be32(1 << 24);
> -	memcpy(hdr + 1, idata, ilen);
> +	if (idata)
> +		memcpy(hdr + 1, idata, ilen);

That would be better as if (ilen) ...

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)