mac80211 may call us with vif == NULL, if the station is not currently
active (e.g., not associated). It is trivially easy to reproduce a crash
by suspending the system when not connected to an AP:
[ 65.533934] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
...
[ 65.574521] pc : ath10k_flush+0x30/0xd0 [ath10k_core]
[ 65.574538] lr : __ieee80211_flush_queues+0x180/0x244 [mac80211]
[ 65.599680] Process kworker/u12:1 (pid: 57, stack limit = 0x(____ptrval____))
[ 65.599682] Call trace:
[ 65.599695] ath10k_flush+0x30/0xd0 [ath10k_core]
[ 65.642064] __ieee80211_flush_queues+0x180/0x244 [mac80211]
[ 65.642079] ieee80211_flush_queues+0x34/0x40 [mac80211]
[ 65.642095] __ieee80211_suspend+0xfc/0x47c [mac80211]
[ 65.658611] ieee80211_suspend+0x30/0x3c [mac80211]
[ 65.658627] wiphy_suspend+0x15c/0x3a8 [cfg80211]
[ 65.672810] dpm_run_callback+0xf0/0x1f0
[ 65.672814] __device_suspend+0x3ac/0x4f8
[ 65.672819] async_suspend+0x34/0xbc
[ 65.684096] async_run_entry_fn+0x54/0x104
[ 65.684099] worker_thread+0x4cc/0x72c
[ 65.684102] kthread+0x134/0x13c
[ 65.684105] ret_from_fork+0x10/0x18
Fixes: 9de4162f09 ("ath10k: add peer flush in ath10k_flush for STATION")
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
d987f783a4