[lvc-project] [PATCH v2] ath9k: hif_usb: Fix use-after-free in ath9k_hif_usb_reg_in_cb()

[Toke Høiland-Jørgensen]

Fedor Pchelkin <pchelkin at ispras.ru> writes:

> It is possible that skb is freed in ath9k_htc_rx_msg(), then
> usb_submit_urb() fails and we try to free skb again. It causes
> use-after-free bug. Moreover, if alloc_skb() fails, urb->context becomes
> NULL but rx_buf is not freed and there can be a memory leak.
>
> The patch removes unnecessary nskb and makes skb processing more clear: it
> is supposed that ath9k_htc_rx_msg() either frees old skb or passes its
> managing to another callback function.
>
> Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
>
> Fixes: 3deff76095c4 ("ath9k_htc: Increase URB count for REG_IN pipe")
> Signed-off-by: Fedor Pchelkin <pchelkin at ispras.ru>
> Signed-off-by: Alexey Khoroshilov <khoroshilov at ispras.ru>

Acked-by: Toke Høiland-Jørgensen <toke at toke.dk>