[PATCH] wifi: mt76: fix oops on non-dbdc mt7986

[Kalle Valo]

Bjørn Mork <bjorn at mork.no> writes:

> mt7915_band_config() sets band_idx = 1 on the main phy for mt7986
> with MT7975_ONE_ADIE or MT7976_ONE_ADIE.
>
> Commit 0335c034e726 ("wifi: mt76: fix race condition related to
> checking tx queue fill status") introduced a dereference of the
> phys array indirectly indexed by band_idx via wcid->phy_idx in
> mt76_wcid_cleanup(). This caused the following Oops on affected
> mt7986 devices:
>
>  Unable to handle kernel read from unreadable memory at virtual address 0000000000000024
>  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
>    CM = 0, WnR = 0
>  user pgtable: 4k pages, 39-bit VAs, pgdp=0000000042545000
>  [0000000000000024] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
>  Internal error: Oops: 0000000096000005 [#1] SMP
>  Modules linked in: ... mt7915e mt76_connac_lib mt76 mac80211 cfg80211 ...
>  CPU: 2 PID: 1631 Comm: hostapd Not tainted 5.15.150 #0
>  Hardware name: ZyXEL EX5700 (Telenor) (DT)
>  pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>  pc : mt76_wcid_cleanup+0x84/0x22c [mt76]
>  lr : mt76_wcid_cleanup+0x64/0x22c [mt76]
>  sp : ffffffc00a803700
>  x29: ffffffc00a803700 x28: ffffff80008f7300 x27: ffffff80003f3c00
>  x26: ffffff80000a7880 x25: ffffffc008c26e00 x24: 0000000000000001
>  x23: ffffffc000a68114 x22: 0000000000000000 x21: ffffff8004172cc8
>  x20: ffffffc00a803748 x19: ffffff8004152020 x18: 0000000000000000
>  x17: 00000000000017c0 x16: ffffffc008ef5000 x15: 0000000000000be0
>  x14: ffffff8004172e28 x13: ffffff8004172e28 x12: 0000000000000000
>  x11: 0000000000000000 x10: ffffff8004172e30 x9 : ffffff8004172e28
>  x8 : 0000000000000000 x7 : ffffff8004156020 x6 : 0000000000000000
>  x5 : 0000000000000031 x4 : 0000000000000000 x3 : 0000000000000001
>  x2 : 0000000000000000 x1 : ffffff80008f7300 x0 : 0000000000000024
>  Call trace:
>   mt76_wcid_cleanup+0x84/0x22c [mt76]
>   __mt76_sta_remove+0x70/0xbc [mt76]
>   mt76_sta_state+0x8c/0x1a4 [mt76]
>   mt7915_eeprom_get_power_delta+0x11e4/0x23a0 [mt7915e]
>   drv_sta_state+0x144/0x274 [mac80211]
>   sta_info_move_state+0x1cc/0x2a4 [mac80211]
>   sta_set_sinfo+0xaf8/0xc24 [mac80211]
>   sta_info_destroy_addr_bss+0x4c/0x6c [mac80211]
>
>   ieee80211_color_change_finish+0x1c08/0x1e70 [mac80211]
>   cfg80211_check_station_change+0x1360/0x4710 [cfg80211]
>   genl_family_rcv_msg_doit+0xb4/0x110
>   genl_rcv_msg+0xd0/0x1bc
>   netlink_rcv_skb+0x58/0x120
>   genl_rcv+0x34/0x50
>   netlink_unicast+0x1f0/0x2ec
>   netlink_sendmsg+0x198/0x3d0
>   ____sys_sendmsg+0x1b0/0x210
>   ___sys_sendmsg+0x80/0xf0
>   __sys_sendmsg+0x44/0xa0
>   __arm64_sys_sendmsg+0x20/0x30
>   invoke_syscall.constprop.0+0x4c/0xe0
>   do_el0_svc+0x40/0xd0
>   el0_svc+0x14/0x4c
>   el0t_64_sync_handler+0x100/0x110
>   el0t_64_sync+0x15c/0x160
>  Code: d2800002 910092c0 52800023 f9800011 (885f7c01)
>  ---[ end trace 7e42dd9a39ed2281 ]---
>
> Fix by using mt76_dev_phy() which will map band_idx to the correct phy
> for all hardware combinations.
>
> Fixes: 0335c034e726 ("wifi: mt76: fix race condition related to checking tx queue fill status")
> Link: https://github.com/openwrt/openwrt/issues/14548
> Signed-off-by: Bjørn Mork <bjorn at mork.no>

Should this go to wireless tree?

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