| Message ID | 20190724123633.10145-1-baijiaju1990@gmail.com (mailing list archive) |
|---|---|
| State | Rejected |
| Delegated to: | Johannes Berg |
| Headers | show |
| Series | [1/2] net: mac80211: Fix possible null-pointer dereferences in ieee80211_setup_sdata() | expand |
On Wed, 2019-07-24 at 20:36 +0800, Jia-Ju Bai wrote: > In ieee80211_xmit_fast_finish(), there is an if statement on line 3356 > to check whether key is NULL: > if (key) > > When key is NULL, it is used on line 3388: > switch (key->conf.cipher) > and line 3393: > pn = atomic64_inc_return(&key->conf.tx_pn); > and line 3396: > crypto_hdr[3] = 0x20 | (key->conf.keyidx << 6); > > Thus, possible null-pointer dereferences may occur. No, this cannot happen, because pn_offs can only be non-zero when there is a key. Maybe we should pass the fast_tx pointer instead of the pn_offs/key from it, but the two are coupled. johannes
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index f13eb2f61ccf..2cc261165b91 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -3381,7 +3381,7 @@ static void ieee80211_xmit_fast_finish(struct ieee80211_sub_if_data *sdata, sta->tx_stats.bytes[skb_get_queue_mapping(skb)] += skb->len; sta->tx_stats.packets[skb_get_queue_mapping(skb)]++; - if (pn_offs) { + if (key && pn_offs) { u64 pn; u8 *crypto_hdr = skb->data + pn_offs;
In ieee80211_xmit_fast_finish(), there is an if statement on line 3356 to check whether key is NULL: if (key) When key is NULL, it is used on line 3388: switch (key->conf.cipher) and line 3393: pn = atomic64_inc_return(&key->conf.tx_pn); and line 3396: crypto_hdr[3] = 0x20 | (key->conf.keyidx << 6); Thus, possible null-pointer dereferences may occur. To fix these bugs, key is checked on line 3384. These bugs are found by a static analysis tool STCheck written by us. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> --- net/mac80211/tx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)