From: Kalle Valo <kvalo@codeaurora.org>
To: Stanislav Yakovlev <stas.yakovlev@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>,
Jeff Garzik <jgarzik@pobox.com>,
James Ketrenos <jketreno@linux.intel.com>,
wireless <linux-wireless@vger.kernel.org>,
kernel-janitors@vger.kernel.org,
Linus Torvalds <torvalds@linuxfoundation.org>
Subject: Re: [PATCH] ipw2x00: potential buffer overflow in libipw_wx_set_encodeext()
Date: Sun, 11 Apr 2021 12:03:11 +0300 [thread overview]
Message-ID: <87blalmbw0.fsf@codeaurora.org> (raw)
In-Reply-To: <CA++WF2PBo1Mok+bnnUCEZxbbEacX7FcU7PYAPTo=iqgOb2+f3Q@mail.gmail.com> (Stanislav Yakovlev's message of "Sat, 10 Apr 2021 10:59:49 +0400")
Stanislav Yakovlev <stas.yakovlev@gmail.com> writes:
> On Tue, 2 Mar 2021 at 15:16, Dan Carpenter <dan.carpenter@oracle.com> wrote:
>>
>> The "ext->key_len" is a u16 that comes from the user. If it's over
>> SCM_KEY_LEN (32) that could lead to memory corruption.
>>
>> Fixes: e0d369d1d969 ("[PATCH] ieee82011: Added WE-18 support to
>> default wireless extension handler")
>> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>> ---
>> drivers/net/wireless/intel/ipw2x00/libipw_wx.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
[...]
>> --- a/drivers/net/wireless/intel/ipw2x00/libipw_wx.c
>> +++ b/drivers/net/wireless/intel/ipw2x00/libipw_wx.c
>> @@ -633,8 +633,10 @@ int libipw_wx_set_encodeext(struct libipw_device *ieee,
>> }
>>
>> if (ext->alg != IW_ENCODE_ALG_NONE) {
>> - memcpy(sec.keys[idx], ext->key, ext->key_len);
>> - sec.key_sizes[idx] = ext->key_len;
>> + int len = min_t(int, ext->key_len, SCM_KEY_LEN);
>> +
>> + memcpy(sec.keys[idx], ext->key, len);
>> + sec.key_sizes[idx] = len;
>> sec.flags |= (1 << idx);
>> if (ext->alg == IW_ENCODE_ALG_WEP) {
>> sec.encode_alg[idx] = SEC_ALG_WEP;
In another thread Linus gave a good tip about clamp_val(), I think it
should be used it here as well to make the check safer and more
readable. And also elsewhere in wireless code with similar limits.
--
https://patchwork.kernel.org/project/linux-wireless/list/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
prev parent reply other threads:[~2021-04-11 9:03 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-02 11:16 [PATCH] ipw2x00: potential buffer overflow in libipw_wx_set_encodeext() Dan Carpenter
2021-04-10 6:59 ` Stanislav Yakovlev
2021-04-11 9:03 ` Kalle Valo [this message]
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