From: Lorenzo Bianconi <lorenzo@kernel.org>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Felix Fietkau <nbd@nbd.name>, Ryder Lee <ryder.lee@mediatek.com>,
Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>,
Roy Luo <royluo@google.com>, Kalle Valo <kvalo@codeaurora.org>,
Matthias Brugger <matthias.bgg@gmail.com>,
linux-wireless@vger.kernel.org,
linux-mediatek@lists.infradead.org,
kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] mt76: mt7615: Use after free in mt7615_mcu_set_bcn()
Date: Sat, 4 May 2019 11:52:16 +0200 [thread overview]
Message-ID: <20190504095215.GA23263@localhost.localdomain> (raw)
In-Reply-To: <20190503130909.GI29695@mwanda>
[-- Attachment #1: Type: text/plain, Size: 1564 bytes --]
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
> We dereference "skb" when we assign:
>
> req.pkt_len = cpu_to_le16(MT_TXD_SIZE + skb->len);
> ^^^^^^^^
> So this patch just moves the dev_kfree_skb() down a bit to avoid the
> use after free.
>
> Fixes: 04b8e65922f6 ("mt76: add mac80211 driver for MT7615 PCIe-based chipsets")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> drivers/net/wireless/mediatek/mt76/mt7615/mcu.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c
> index ea67c6022fe6..dc1301effa24 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c
> @@ -1270,7 +1270,6 @@ int mt7615_mcu_set_bcn(struct mt7615_dev *dev, struct ieee80211_vif *vif,
> mt7615_mac_write_txwi(dev, (__le32 *)(req.pkt), skb, wcid, NULL,
> 0, NULL);
> memcpy(req.pkt + MT_TXD_SIZE, skb->data, skb->len);
> - dev_kfree_skb(skb);
>
> req.omac_idx = mvif->omac_idx;
> req.enable = en;
> @@ -1281,6 +1280,7 @@ int mt7615_mcu_set_bcn(struct mt7615_dev *dev, struct ieee80211_vif *vif,
> req.pkt_len = cpu_to_le16(MT_TXD_SIZE + skb->len);
> req.tim_ie_pos = cpu_to_le16(MT_TXD_SIZE + tim_off);
>
> + dev_kfree_skb(skb);
> skb = mt7615_mcu_msg_alloc(&req, sizeof(req));
>
> return mt7615_mcu_msg_send(dev, skb, MCU_EXT_CMD_BCN_OFFLOAD,
> --
> 2.18.0
>
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]
prev parent reply other threads:[~2019-05-04 9:52 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-03 13:09 [PATCH] mt76: mt7615: Use after free in mt7615_mcu_set_bcn() Dan Carpenter
2019-05-04 9:52 ` Lorenzo Bianconi [this message]
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=20190504095215.GA23263@localhost.localdomain \
--to=lorenzo@kernel.org \
--cc=dan.carpenter@oracle.com \
--cc=kernel-janitors@vger.kernel.org \
--cc=kvalo@codeaurora.org \
--cc=linux-mediatek@lists.infradead.org \
--cc=linux-wireless@vger.kernel.org \
--cc=lorenzo.bianconi83@gmail.com \
--cc=matthias.bgg@gmail.com \
--cc=nbd@nbd.name \
--cc=royluo@google.com \
--cc=ryder.lee@mediatek.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).