| Message ID | 20210502202545.1405-1-phil@philpotter.co.uk (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | ath9k: ath9k_htc_rx_msg: return when sk_buff is too small | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
Phillip Potter <phil@philpotter.co.uk> wrote: > At the start of ath9k_htc_rx_msg, we check to see if the skb pointer is > valid, but what we don't do is check if it is large enough to contain a > valid struct htc_frame_hdr. We should check for this and return, as the > buffer is invalid in this case. Fixes a KMSAN-found uninit-value bug > reported by syzbot at: > https://syzkaller.appspot.com/bug?id=7dccb7d9ad4251df1c49f370607a49e1f09644ee > > Reported-by: syzbot+e4534e8c1c382508312c@syzkaller.appspotmail.com > Signed-off-by: Phillip Potter <phil@philpotter.co.uk> > --- > drivers/net/wireless/ath/ath9k/htc_hst.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/wireless/ath/ath9k/htc_hst.c b/drivers/net/wireless/ath/ath9k/htc_hst.c > index 510e61e97dbc..9dbfff7a388e 100644 > --- a/drivers/net/wireless/ath/ath9k/htc_hst.c > +++ b/drivers/net/wireless/ath/ath9k/htc_hst.c > @@ -403,7 +403,7 @@ void ath9k_htc_rx_msg(struct htc_target *htc_handle, > struct htc_endpoint *endpoint; > __be16 *msg_id; > > - if (!htc_handle || !skb) > + if (!htc_handle || !skb || !pskb_may_pull(skb, sizeof(struct htc_frame_hdr))) > return; This leaks the skb.
On Sun, May 02, 2021 at 10:28:27PM +0200, Florian Westphal wrote: > Phillip Potter <phil@philpotter.co.uk> wrote: > > At the start of ath9k_htc_rx_msg, we check to see if the skb pointer is > > valid, but what we don't do is check if it is large enough to contain a > > valid struct htc_frame_hdr. We should check for this and return, as the > > buffer is invalid in this case. Fixes a KMSAN-found uninit-value bug > > reported by syzbot at: > > https://syzkaller.appspot.com/bug?id=7dccb7d9ad4251df1c49f370607a49e1f09644ee > > > > Reported-by: syzbot+e4534e8c1c382508312c@syzkaller.appspotmail.com > > Signed-off-by: Phillip Potter <phil@philpotter.co.uk> > > --- > > drivers/net/wireless/ath/ath9k/htc_hst.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/net/wireless/ath/ath9k/htc_hst.c b/drivers/net/wireless/ath/ath9k/htc_hst.c > > index 510e61e97dbc..9dbfff7a388e 100644 > > --- a/drivers/net/wireless/ath/ath9k/htc_hst.c > > +++ b/drivers/net/wireless/ath/ath9k/htc_hst.c > > @@ -403,7 +403,7 @@ void ath9k_htc_rx_msg(struct htc_target *htc_handle, > > struct htc_endpoint *endpoint; > > __be16 *msg_id; > > > > - if (!htc_handle || !skb) > > + if (!htc_handle || !skb || !pskb_may_pull(skb, sizeof(struct htc_frame_hdr))) > > return; > > This leaks the skb. Dear Florian, Thank you, and apologies, I shall resend. Not sure how I missed that. Regards, Phil
diff --git a/drivers/net/wireless/ath/ath9k/htc_hst.c b/drivers/net/wireless/ath/ath9k/htc_hst.c index 510e61e97dbc..9dbfff7a388e 100644 --- a/drivers/net/wireless/ath/ath9k/htc_hst.c +++ b/drivers/net/wireless/ath/ath9k/htc_hst.c @@ -403,7 +403,7 @@ void ath9k_htc_rx_msg(struct htc_target *htc_handle, struct htc_endpoint *endpoint; __be16 *msg_id; - if (!htc_handle || !skb) + if (!htc_handle || !skb || !pskb_may_pull(skb, sizeof(struct htc_frame_hdr))) return; htc_hdr = (struct htc_frame_hdr *) skb->data;
At the start of ath9k_htc_rx_msg, we check to see if the skb pointer is valid, but what we don't do is check if it is large enough to contain a valid struct htc_frame_hdr. We should check for this and return, as the buffer is invalid in this case. Fixes a KMSAN-found uninit-value bug reported by syzbot at: https://syzkaller.appspot.com/bug?id=7dccb7d9ad4251df1c49f370607a49e1f09644ee Reported-by: syzbot+e4534e8c1c382508312c@syzkaller.appspotmail.com Signed-off-by: Phillip Potter <phil@philpotter.co.uk> --- drivers/net/wireless/ath/ath9k/htc_hst.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)