ath10k: fix null deref on wmi-tlv when trying spectral scan
commit
18ae68fff392e445af3c2d8be9bef8a16e1c72a7 upstream.
WMI ops wrappers did not properly check for null
function pointers for spectral scan. This caused
null dereference crash with WMI-TLV based firmware
which doesn't implement spectral scan.
The crash could be triggered with:
ip link set dev wlan0 up
echo background > /sys/kernel/debug/ieee80211/phy0/ath10k/spectral_scan_ctl
The crash looked like this:
[ 168.031989] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 168.037406] IP: [< (null)>] (null)
[ 168.040395] PGD cdd4067 PUD fa0f067 PMD 0
[ 168.043303] Oops: 0010 [#1] SMP
[ 168.045377] Modules linked in: ath10k_pci(O) ath10k_core(O) ath mac80211 cfg80211 [last unloaded: cfg80211]
[ 168.051560] CPU: 1 PID: 1380 Comm: bash Tainted: G W O 4.8.0 #78
[ 168.054336] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[ 168.059183] task:
ffff88000c460c00 task.stack:
ffff88000d4bc000
[ 168.061736] RIP: 0010:[<
0000000000000000>] [< (null)>] (null)
...
[ 168.100620] Call Trace:
[ 168.101910] [<
ffffffffa03b9566>] ? ath10k_spectral_scan_config+0x96/0x200 [ath10k_core]
[ 168.104871] [<
ffffffff811386e2>] ? filemap_fault+0xb2/0x4a0
[ 168.106696] [<
ffffffffa03b97e6>] write_file_spec_scan_ctl+0x116/0x280 [ath10k_core]
[ 168.109618] [<
ffffffff812da3a1>] full_proxy_write+0x51/0x80
[ 168.111443] [<
ffffffff811957b8>] __vfs_write+0x28/0x120
[ 168.113090] [<
ffffffff812f1a2d>] ? security_file_permission+0x3d/0xc0
[ 168.114932] [<
ffffffff8109b912>] ? percpu_down_read+0x12/0x60
[ 168.116680] [<
ffffffff811965f8>] vfs_write+0xb8/0x1a0
[ 168.118293] [<
ffffffff81197966>] SyS_write+0x46/0xa0
[ 168.119912] [<
ffffffff818f2972>] entry_SYSCALL_64_fastpath+0x1a/0xa4
[ 168.121737] Code: Bad RIP value.
[ 168.123318] RIP [< (null)>] (null)
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>