I have reproduced this on linux 6.5.0-rc5 with more debug info and source line pointers.
I get the impression that the firmware generates a rssi notification, even after it has disconnected from the AP.
Looking into the
> BUG: KASAN: null-ptr-deref in cfg80211_cqm_rssi_notify (/home/r/linux/net/wireless/nl80211.c:19089) cfg80211
with source context:
net/wireless/nl80211.c
19069 void cfg80211_cqm_rssi_notify(struct net_device *dev,
...
19082
19083 if (wdev->cqm_config) {
19084 wdev->cqm_config->last_rssi_event_value = rssi_level;
19085
19086 cfg80211_cqm_rssi_update(rdev, dev);
19087
19088 if (rssi_level == 0)
19089 rssi_level = wdev->cqm_config->last_rssi_event_value;
19090 }
19091
it looks like the cfg80211_cqm_rssi_update would unset the ->cqm_config, as the firmware is telling us, that there is (currently) no station
> brcmfmac: brcmf_fil_cmd_data Firmware error: BCME_NOTFOUND (-30)
> brcmfmac: brcmf_fil_iovar_data_get ifidx=0, name=tdls_sta_info, len=296, err=-52
> brcmfmac: brcmf_fil_cmd_data Firmware error: BCME_BADADDR (-21)
> brcmfmac: brcmf_fil_iovar_data_get ifidx=0, name=sta_info, len=296, err=-52
> ieee80211 phy0: brcmf_cfg80211_get_station: GET STA INFO failed, -52
And then we have the null pointer at
19088 if (rssi_level == 0)
19089 --> rssi_level = wdev->cqm_config->last_rssi_event_value;
19090 }
So my suggestion would be to do
19088 if (rssi_level == 0 && wdev->cqm_config) // config has not been deleted / station deleted in the meantime
19089 rssi_level = wdev->cqm_config->last_rssi_event_value;
19090 }
Any opinions?
Best,
Max
(nota: the interleaved brcmdata in between the KASAN report are original)
wpa_supplicant[332]: wlan0: CTRL-EVENT-DISCONNECTED bssid=XX:XX:XX:XX:74:1f reason=3 locally_generated=1
systemd[1]: Stopping User Manager for UID 1000...
brcmfmac: brcmf_rx_event Enter: mmc1:0001:1: rxp=0000000017163222
brcmfmac: brcmf_fweh_event_worker event LINK (16) ifidx 0 bsscfg 0 addr xx:xx:xx:xx:74:1f
brcmfmac: brcmf_fweh_event_worker version 2 flags 0 status 0 reason 2
brcmutil: event payload, len=0
brcmfmac: brcmf_is_linkdown Processing link down
brcmfmac: brcmf_notify_connect_status Linkdown
brcmfmac: brcmf_rx_event Enter: mmc1:0001:1: rxp=00000000dcf7c0c0
brcmfmac: brcmf_fweh_event_worker event RSSI (56) ifidx 0 bsscfg 0 addr 00:00:xx:xx:00:50
brcmfmac: brcmf_fweh_event_worker version 2 flags 0 status 0 reason 0
brcmutil: event payload, len=12
00000000: 00 00 00 00 00 00 00 00 00 00 00 00 ............
brcmfmac: brcmf_notify_rssi LOW rssi=0
brcmfmac: brcmf_cfg80211_del_key key index (0)
brcmfmac: brcmf_cfg80211_del_key Ignore clearing of (never configured) key
brcmfmac: brcmf_cfg80211_del_key key index (1)
brcmfmac: brcmf_cfg80211_del_key Ignore clearing of (never configured) key
brcmfmac: brcmf_cfg80211_del_key key index (2)
brcmfmac: brcmf_cfg80211_del_key Ignore clearing of (never configured) key
brcmfmac: brcmf_cfg80211_del_key key index (3)
brcmfmac: brcmf_cfg80211_del_key Ignore clearing of (never configured) key
brcmfmac: brcmf_cfg80211_del_key key index (4)
brcmfmac: brcmf_cfg80211_del_key Ignore clearing of (never configured) key
brcmfmac: brcmf_cfg80211_del_key key index (5)
brcmfmac: brcmf_cfg80211_del_key Ignore clearing of (never configured) key
brcmfmac: brcmf_fil_cmd_data Firmware error: BCME_NOTFOUND (-30)
brcmfmac: brcmf_fil_iovar_data_get ifidx=0, name=tdls_sta_info, len=296, err=-52
brcmutil: data
00000000: 34 2c c4 3a 74 1f 00 00 00 00 00 00 00 00 00 00 4,.:t...........
00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
brcmfmac: brcmf_fil_cmd_data Firmware error: BCME_BADADDR (-21)
brcmfmac: brcmf_fil_iovar_data_get ifidx=0, name=sta_info, len=296, err=-52
brcmutil: data
00000000: 34 2c c4 3a 74 1f 00 00 00 00 00 00 00 00 00 00 4,.:t...........
00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
ieee80211 phy0: brcmf_cfg80211_get_station: GET STA INFO failed, -52
==================================================================
BUG: KASAN: null-ptr-deref in cfg80211_cqm_rssi_notify (/home/r/linux/net/wireless/nl80211.c:19089) cfg80211
Read of size 4 at addr 0000000000000004 by task kworker/1:2/126
kernel:
CPU: 1 PID: 126 Comm: kworker/1:2 Tainted: G C 6.5.0-rc5-v8-g1af52ad6a306 #2
Hardware name: Raspberry Pi Compute Module 4 Rev 1.0 (DT)
Workqueue: events brcmf_fweh_event_worker [brcmfmac]
Call trace:
dump_backtrace (/home/r/linux/arch/arm64/kernel/stacktrace.c:235)
show_stack (/home/r/linux/arch/arm64/kernel/stacktrace.c:242)
dump_stack_lvl (/home/r/linux/lib/dump_stack.c:107)
kasan_report (/home/r/linux/mm/kasan/report.c:590)
__asan_load4 (/home/r/linux/mm/kasan/generic.c:259)
brcmfmac: brcmf_fil_iovar_data_set ifidx=0, name=rssi_event, len=16
brcmutil: data
00000000: 00 00 00 00 03 00 00 7f 00 00 00 00 00 00 00 00 ................
cfg80211_cqm_rssi_notify (/home/r/linux/net/wireless/nl80211.c:19089) cfg80211
brcmf_notify_rssi (/home/r/linux/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c:6651) brcmfmac
brcmf_fweh_call_event_handler (/home/r/linux/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c:109) brcmfmac
brcmf_fweh_event_worker (/home/r/linux/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c:268) brcmfmac
process_one_work (/home/r/linux/./arch/arm64/include/asm/jump_label.h:21 /home/r/linux/./include/linux/jump_label.h:207 /home/r/linux/./include/trace/events/workqueue.h:108 /home/r/linux/kernel/workqueue.c:2602)
worker_thread (/home/r/linux/./include/linux/list.h:292 /home/r/linux/kernel/workqueue.c:2749)
kthread (/home/r/linux/kernel/kthread.c:389)
ret_from_fork (/home/r/linux/arch/arm64/kernel/entry.S:854)
==================================================================
Disabling lock debugging due to kernel taint
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004
Mem abort info:
ESR = 0x0000000096000005
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x05: level 1 translation fault
Data abort info:
ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
user pgtable: 4k pages, 39-bit VAs, pgdp=000000004848b000
[0000000000000004] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
Modules linked in: brcmfmac_wcc vc4 brcmfmac snd_soc_hdmi_codec cfg80211 snd_soc_core snd_pcm_dmaengine rtc_pcf85063 snd_pcm regmap_i2c snd_timer rpivid_hevc(C) snd xt_tcpudp nft_compat bcm2835_isp(C) nf_tables drm_display_helper bcm2835_mmal_vchiq(C) videobuf2_dma_contig v3d drm_dma_helper videobuf2_memops v4l2_mem2mem videobuf2_v4l2 videodev nfnetlink drm_shmem_helper drm_kms_helper gpu_sched i2c_mux_pinctrl gpio_keys raspberrypi_hwmon i2c_mux i2c_brcmstb rfkill joydev hid_microsoft videobuf2_common ff_memless brcmutil i2c_bcm2835 mc vc_sm_cma(C) cec nvmem_rmem uio_pdrv_genirq uio drm fuse drm_panel_orientation_quirks backlight ip_tables x_tables ipv6
CPU: 1 PID: 126 Comm: kworker/1:2 Tainted: G B C 6.5.0-rc5-v8-g1af52ad6a306 #2
Hardware name: Raspberry Pi Compute Module 4 Rev 1.0 (DT)
Workqueue: events brcmf_fweh_event_worker [brcmfmac]
pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : cfg80211_cqm_rssi_notify (/home/r/linux/net/wireless/nl80211.c:19089) cfg80211
lr : cfg80211_cqm_rssi_notify (/home/r/linux/net/wireless/nl80211.c:19089) cfg80211
sp : ffffffc0808f7a10
x29: ffffffc0808f7a10 x28: ffffff80432d0a68 x27: ffffff804b1d4368
x26: ffffff80432d03c0 x25: 1ffffff81011ef4e x24: ffffff8049b6fbc0
x23: 0000000000000cc0 x22: 0000000000000000 x21: ffffff804b1d4008
x20: 0000000000000000 x19: ffffff8048096000 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
x14: 0000000000000000 x13: 746e696174206c65 x12: ffffffbcc23e1e29
x11: 1ffffffcc23e1e28 x10: ffffffbcc23e1e28 x9 : dfffffc000000000
x8 : 000000433dc1e1d8 x7 : ffffffe611f0f147 x6 : 0000000000000001
x5 : ffffffe611f0f140 x4 : ffffffbcc23e1e29 x3 : ffffffe60f6c0924
x2 : 0000000000000000 x1 : ffffff80469f4000 x0 : 0000000000000001
Call trace:
cfg80211_cqm_rssi_notify (/home/r/linux/net/wireless/nl80211.c:19089) cfg80211
brcmf_notify_rssi (/home/r/linux/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c:6651) brcmfmac
brcmf_fweh_call_event_handler (/home/r/linux/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c:109) brcmfmac
brcmf_fweh_event_worker (/home/r/linux/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c:268) brcmfmac
process_one_work (/home/r/linux/./arch/arm64/include/asm/jump_label.h:21 /home/r/linux/./include/linux/jump_label.h:207 /home/r/linux/./include/trace/events/workqueue.h:108 /home/r/linux/kernel/workqueue.c:2602)
worker_thread (/home/r/linux/./include/linux/list.h:292 /home/r/linux/kernel/workqueue.c:2749)
kthread (/home/r/linux/kernel/kthread.c:389)
ret_from_fork (/home/r/linux/arch/arm64/kernel/entry.S:854)
Code: 9401bd51 f941b2b4 91001280 9401bd48 (b9400694)
All code
========
0: 9401bd51 bl 0x6f544
4: f941b2b4 ldr x20, [x21, #864]
8: 91001280 add x0, x20, #0x4
c: 9401bd48 bl 0x6f52c
10:* b9400694 ldr w20, [x20, #4] <-- trapping instruction
Code starting with the faulting instruction
===========================================
0: b9400694 ldr w20, [x20, #4]
---[ end trace 0000000000000000 ]---
brcmfmac: brcmf_fil_iovar_data_get ifidx=0, name=country, len=12, err=0
brcmutil: data
00000000: 44 45 00 00 00 00 00 00 44 45 00 41 DE......DE.A
brcmfmac: brcmf_rx_event Enter: mmc1:0001:1: rxp=0000000068d7cc22
brcmfmac: brcmf_fil_iovar_data_get ifidx=0, name=qtxpower, len=4, err=0
