Subject: [PATCH] mac80211: set up the fwd_skb->dev for mesh forwarding
From: Xing Song <[email-masked]>
Date: Tue, 23 Nov 2021 11:31:23 +0800

Mesh forwarding requires that the fwd_skb->dev is set up for TX handling,
otherwise the following warning will be generated, so set it up for the
pending frames.

[   72.835674 ] WARNING: CPU: 0 PID: 1193 at __skb_flow_dissect+0x284/0x1298
[   72.842379 ] Modules linked in: ksmbd pppoe ppp_async l2tp_ppp ...
[   72.962020 ] CPU: 0 PID: 1193 Comm: kworker/u5:1 Tainted: P S 5.4.137 #0
[   72.969938 ] Hardware name: MT7622_MT7531 RFB (DT)
[   72.974659 ] Workqueue: napi_workq napi_workfn
[   72.979025 ] pstate: 60000005 (nZCv daif -PAN -UAO)
[   72.983822 ] pc : __skb_flow_dissect+0x284/0x1298
[   72.988444 ] lr : __skb_flow_dissect+0x54/0x1298
[   72.992977 ] sp : ffffffc010c738c0
[   72.996293 ] x29: ffffffc010c738c0 x28: 0000000000000000
[   73.001615 ] x27: 000000000000ffc2 x26: ffffff800c2eb818
[   73.006937 ] x25: ffffffc010a987c8 x24: 00000000000000ce
[   73.012259 ] x23: ffffffc010c73a28 x22: ffffffc010a99c60
[   73.017581 ] x21: 000000000000ffc2 x20: ffffff80094da800
[   73.022903 ] x19: 0000000000000000 x18: 0000000000000014
[   73.028226 ] x17: 00000000084d16af x16: 00000000d1fc0bab
[   73.033548 ] x15: 00000000715f6034 x14: 000000009dbdd301
[   73.038870 ] x13: 00000000ea4dcbc3 x12: 0000000000000040
[   73.044192 ] x11: 000000000eb00ff0 x10: 0000000000000000
[   73.049513 ] x9 : 000000000eb00073 x8 : 0000000000000088
[   73.054834 ] x7 : 0000000000000000 x6 : 0000000000000001
[   73.060155 ] x5 : 0000000000000000 x4 : 0000000000000000
[   73.065476 ] x3 : ffffffc010a98000 x2 : 0000000000000000
[   73.070797 ] x1 : 0000000000000000 x0 : 0000000000000000
[   73.076120 ] Call trace:
[   73.078572 ]  __skb_flow_dissect+0x284/0x1298
[   73.082846 ]  __skb_get_hash+0x7c/0x228
[   73.086629 ]  ieee80211_txq_may_transmit+0x7fc/0x17b8 [mac80211]
[   73.092564 ]  ieee80211_tx_prepare_skb+0x20c/0x268 [mac80211]
[   73.098238 ]  ieee80211_tx_pending+0x144/0x330 [mac80211]
[   73.103560 ]  tasklet_action_common.isra.16+0xb4/0x158
[   73.108618 ]  tasklet_action+0x2c/0x38
[   73.112286 ]  __do_softirq+0x168/0x3b0
[   73.115954 ]  do_softirq.part.15+0x88/0x98
[   73.119969 ]  __local_bh_enable_ip+0xb0/0xb8
[   73.124156 ]  napi_workfn+0x58/0x90
[   73.127565 ]  process_one_work+0x20c/0x478
[   73.131579 ]  worker_thread+0x50/0x4f0
[   73.135249 ]  kthread+0x124/0x128
[   73.138484 ]  ret_from_fork+0x10/0x1c

Signed-off-by: Xing Song <[email-masked]>
---

--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2950,6 +2950,7 @@ ieee80211_rx_h_mesh_fwding(struct ieee80
 	if (!fwd_skb)
 		goto out;
 
+	fwd_skb->dev = sdata->dev;
 	fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
 	fwd_hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_RETRY);
 	info = IEEE80211_SKB_CB(fwd_skb);