On 2022/10/26 13:46, Ping-Ke Shih wrote:
-----Original Message----- From: Zhengchao Shao <shaozhengchao@xxxxxxxxxx> Sent: Wednesday, October 26, 2022 10:47 AM To: linux-wireless@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; johannes@xxxxxxxxxxxxxxxx; davem@xxxxxxxxxxxxx; edumazet@xxxxxxxxxx; kuba@xxxxxxxxxx; pabeni@xxxxxxxxxx Cc: toke@xxxxxxxxxx; alexander@xxxxxxxxxxxxxx; nbd@xxxxxxxx; weiyongjun1@xxxxxxxxxx; yuehaibing@xxxxxxxxxx; shaozhengchao@xxxxxxxxxx Subject: [PATCH net,v2] wifi: mac80211: fix general-protection-fault in ieee80211_subif_start_xmit() When device is running and the interface status is changed, the gpf issue is triggered. The problem triggering process is as follows: Thread A: Thread B ieee80211_runtime_change_iftype() process_one_work() ... ... ieee80211_do_stop() ... ... ... sdata->bss = NULL ... ... ieee80211_subif_start_xmit() ieee80211_multicast_to_unicast //!sdata->bss->multicast_to_unicast cause gpf issue When the interface status is changed, the sending queue continues to send packets. After the bss is set to NULL, the bss is accessed. As a result, this causes a general-protection-fault issue. The following is the stack information: general protection fault, probably for non-canonical address 0xdffffc000000002f: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000178-0x000000000000017f] Workqueue: mld mld_ifc_work RIP: 0010:ieee80211_subif_start_xmit+0x25b/0x1310 Call Trace: <TASK> dev_hard_start_xmit+0x1be/0x990 __dev_queue_xmit+0x2c9a/0x3b60 ip6_finish_output2+0xf92/0x1520 ip6_finish_output+0x6af/0x11e0 ip6_output+0x1ed/0x540 mld_sendpack+0xa09/0xe70 mld_ifc_work+0x71c/0xdb0 process_one_work+0x9bf/0x1710 worker_thread+0x665/0x1080 kthread+0x2e4/0x3a0 ret_from_fork+0x1f/0x30 </TASK> Fixes: f856373e2f31 ("wifi: mac80211: do not wake queues on a vif that is being stopped") Reported-by: syzbot+c6e8fca81c294fd5620a@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Zhengchao Shao <shaozhengchao@xxxxxxxxxx> --- net/mac80211/tx.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index a364148149f9..c38485f39d2b 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -4418,6 +4418,11 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb, if (likely(!is_multicast_ether_addr(eth->h_dest))) goto normal; + if (unlikely(!ieee80211_sdata_running(sdata))) { + kfree_skb(skb); + return NETDEV_TX_OK; + } +The indent looks odd. It seems like you use spaces instead of tabs?
Hi Shih: Thank you for your review. I will fix it in V3. Zhengchao Shao
if (unlikely(ieee80211_multicast_to_unicast(skb, dev))) { struct sk_buff_head queue; -- 2.17.1 ------Please consider the environment before printing this e-mail.
