Ping-Ke Shih <pkshih@xxxxxxxxxxx> wrote:
> A race condition can happen if netdev is registered, but NAPI isn't
> initialized yet, and meanwhile user space starts the netdev that will
> enable NAPI. Then, it hits BUG_ON():
>
> kernel BUG at net/core/dev.c:6423!
> invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
> CPU: 0 PID: 417 Comm: iwd Not tainted 6.2.7-slab-dirty #3 eb0f5a8a9d91
> Hardware name: LENOVO 21DL/LNVNB161216, BIOS JPCN20WW(V1.06) 09/20/2022
> RIP: 0010:napi_enable+0x3f/0x50
> Code: 48 89 c2 48 83 e2 f6 f6 81 89 08 00 00 02 74 0d 48 83 ...
> RSP: 0018:ffffada1414f3548 EFLAGS: 00010246
> RAX: 0000000000000000 RBX: ffffa01425802080 RCX: 0000000000000000
> RDX: 00000000000002ff RSI: ffffada14e50c614 RDI: ffffa01425808dc0
> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000001 R11: 0000000000000100 R12: ffffa01425808f58
> R13: 0000000000000000 R14: ffffa01423498940 R15: 0000000000000001
> FS: 00007f5577c0a740(0000) GS:ffffa0169fc00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f5577a19972 CR3: 0000000125a7a000 CR4: 0000000000750ef0
> PKRU: 55555554
> Call Trace:
> <TASK>
> rtw89_pci_ops_start+0x1c/0x70 [rtw89_pci 6cbc75429515c181cbc386478d5cfb32ffc5a0f8]
> rtw89_core_start+0xbe/0x160 [rtw89_core fe07ecb874820b6d778370d4acb6ef8a37847f22]
> rtw89_ops_start+0x26/0x40 [rtw89_core fe07ecb874820b6d778370d4acb6ef8a37847f22]
> drv_start+0x42/0x100 [mac80211 c07fa22af8c3cf3f7d7ab3884ca990784d72e2d2]
> ieee80211_do_open+0x311/0x7d0 [mac80211 c07fa22af8c3cf3f7d7ab3884ca990784d72e2d2]
> ieee80211_open+0x6a/0x90 [mac80211 c07fa22af8c3cf3f7d7ab3884ca990784d72e2d2]
> __dev_open+0xe0/0x180
> __dev_change_flags+0x1da/0x250
> dev_change_flags+0x26/0x70
> do_setlink+0x37c/0x12c0
> ? ep_poll_callback+0x246/0x290
> ? __nla_validate_parse+0x61/0xd00
> ? __wake_up_common_lock+0x8f/0xd0
>
> To fix this, follow Jonas' suggestion to switch the order of these
> functions and move register netdev to be the last step of PCI probe.
> Also, correct the error handling of rtw89_core_register_hw().
>
> Fixes: e3ec7017f6a2 ("rtw89: add Realtek 802.11ax driver")
> Cc: stable@xxxxxxxxxxxxxxx
> Reported-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
> Link: https://lore.kernel.org/linux-wireless/CAOiHx=n7EwK2B9CnBR07FVA=sEzFagb8TkS4XC_qBNq8OwcYUg@xxxxxxxxxxxxxx/T/#t
> Suggested-by: Jonas Gorski <jonas.gorski@xxxxxxxxx>
> Tested-by: Larry Finger<Larry.Finger@xxxxxxxxxxxx>
> Reviewed-by: Larry Finger<Larry.Finger@xxxxxxxxxxxx>
> Signed-off-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx>
Patch applied to wireless-next.git, thanks.
47515664ecfb wifi: rtw89: fix potential race condition between napi_init and napi_enable
--
https://patchwork.kernel.org/project/linux-wireless/patch/20230323082839.20474-1-pkshih@xxxxxxxxxxx/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
