From: Zhengchao Shao shaozhengchao@huawei.com
[ Upstream commit 780854186946e0de2be192ee7fa5125666533b3a ]
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@syzkaller.appspotmail.com Signed-off-by: Zhengchao Shao shaozhengchao@huawei.com Link: https://lore.kernel.org/r/20221026063959.177813-1-shaozhengchao@huawei.com Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/mac80211/tx.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 13249e97a069..d2c4f9226f94 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -4379,6 +4379,11 @@ 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; + } + if (unlikely(ieee80211_multicast_to_unicast(skb, dev))) { struct sk_buff_head queue;