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Mark Anthony AgarroandFelix Fietkau
be5ce79105
Tearing down a monitor interface oopses:
BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:mt76_connac_mcu_uni_add_bss+0x144/0x370 [mt76_connac_lib]
Call Trace:
mt7615_remove_interface+0x6a/0x200 [mt7615_common]
drv_remove_interface+0x60/0x140 [mac80211]
ieee80211_del_virtual_monitor+0x8f/0xc0 [mac80211]
ieee80211_do_open+0x550/0x7d0 [mac80211]
ieee80211_open+0xaa/0xb0 [mac80211]
__dev_open+0x11b/0x280
mt7615_remove_interface() tears down BSS and STA state for every vif type.
On MT7663 with offload firmware that reaches mt76_connac_mcu_uni_add_bss(),
which has no monitor case in its iftype switch. It takes WARN_ON(1), then
copies ETH_ALEN from vif->bss_conf.bssid, which is NULL for a monitor vif.
mt76_connac_mcu_bss_basic_tlv() in the same file handles this. It has an
NL80211_IFTYPE_MONITOR case and it copies phy->macaddr in place of the
bssid. The uni variant has neither.
There is nothing to tear down. mt7615_add_interface() only calls
mt7615_mcu_add_dev_info(). The BSS and STA state comes from beacon enable
in mt7615_bss_info_changed(), from mt7615_set_key() and from
mt7615_mac_sta_add(), so a monitor vif never has any.
Reported on mt7615e going from monitor back to managed, and on mt7663u on
an "ip link set down", both through ieee80211_del_virtual_monitor().
Fixes: d9852ab2f362 ("mt76: mt7615: keep mcu_add_bss_info enabled till interface removal")
Cc: [email protected]
Reported-by: Orly Orge <[email protected]>
Closes: https://lore.kernel.org/linux-wireless/CANj5C4mTOHs6riyWee=dFdkE5p=714J8xs-x3hq3ewQ+r6O_Nw@mail.gmail.com/
Reported-by: Inanix <[email protected]>
Closes: https://github.com/morrownr/mt76/issues/79
Tested-by: Inanix <[email protected]>
Signed-off-by: Mark Anthony Agarro <[email protected]>
Signed-off-by: Devin Wittmayer <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Felix Fietkau <[email protected]>