linux-wireless.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Kalle Valo <kvalo@codeaurora.org>
To: Xiaohui Zhang <ruc_zhangxiaohui@163.com>
Cc: Amitkumar Karwar <amitkarwar@gmail.com>,
	Ganapathi Bhat <ganapathi.bhat@nxp.com>,
	Xinming Hu <huxinming820@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] mwifiex: Fix possible buffer overflows in mwifiex_uap_bss_param_prepare
Date: Tue, 08 Dec 2020 16:28:53 +0200	[thread overview]
Message-ID: <87blf4e5i2.fsf@codeaurora.org> (raw)
In-Reply-To: <20201208113607.24967-1-ruc_zhangxiaohui@163.com> (Xiaohui Zhang's message of "Tue, 8 Dec 2020 19:36:07 +0800")

Xiaohui Zhang <ruc_zhangxiaohui@163.com> writes:

> From: Zhang Xiaohui <ruc_zhangxiaohui@163.com>
>
> mwifiex_uap_bss_param_prepare() calls memcpy() without checking
> the destination size may trigger a buffer overflower,
> which a local user could use to cause denial of service or the
> execution of arbitrary code.
> Fix it by putting the length check before calling memcpy().
>
> Signed-off-by: Zhang Xiaohui <ruc_zhangxiaohui@163.com>
> ---
>  drivers/net/wireless/marvell/mwifiex/uap_cmd.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/marvell/mwifiex/uap_cmd.c b/drivers/net/wireless/marvell/mwifiex/uap_cmd.c
> index b48a85d79..fb937c7ee 100644
> --- a/drivers/net/wireless/marvell/mwifiex/uap_cmd.c
> +++ b/drivers/net/wireless/marvell/mwifiex/uap_cmd.c
> @@ -496,13 +496,16 @@ mwifiex_uap_bss_param_prepare(u8 *tlv, void *cmd_buf, u16 *param_size)
>  	struct mwifiex_ie_types_wmmcap *wmm_cap;
>  	struct mwifiex_uap_bss_param *bss_cfg = cmd_buf;
>  	int i;
> +	int ssid_size;
>  	u16 cmd_size = *param_size;
>  
>  	if (bss_cfg->ssid.ssid_len) {
>  		ssid = (struct host_cmd_tlv_ssid *)tlv;
>  		ssid->header.type = cpu_to_le16(TLV_TYPE_UAP_SSID);
>  		ssid->header.len = cpu_to_le16((u16)bss_cfg->ssid.ssid_len);
> -		memcpy(ssid->ssid, bss_cfg->ssid.ssid, bss_cfg->ssid.ssid_len);
> +		ssid_size = bss_cfg->ssid.ssid_len > strlen(ssid->ssid) ?
> +				strlen(ssid->ssid) : bss_cfg->ssid.ssid_len;
> +		memcpy(ssid->ssid, bss_cfg->ssid.ssid, ssid_size);

I think using min_t() is cleaner. Then you would not need to add a
temporary variable.

-- 
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

  reply	other threads:[~2020-12-08 14:30 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-08 11:36 [PATCH 1/1] mwifiex: Fix possible buffer overflows in mwifiex_uap_bss_param_prepare Xiaohui Zhang
2020-12-08 14:28 ` Kalle Valo [this message]
  -- strict thread matches above, loose matches on Subject: below --
2020-12-08 15:43 Xiaohui Zhang
2020-12-08 16:05 ` Kalle Valo
2020-12-08 18:56 ` Brian Norris

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87blf4e5i2.fsf@codeaurora.org \
    --to=kvalo@codeaurora.org \
    --cc=amitkarwar@gmail.com \
    --cc=davem@davemloft.net \
    --cc=ganapathi.bhat@nxp.com \
    --cc=huxinming820@gmail.com \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-wireless@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=ruc_zhangxiaohui@163.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).