4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zhi Chen <zhichen@xxxxxxxxxxxxxx> commit c8291988806407e02a01b4b15b4504eafbcc04e0 upstream. Length of WMI scan message was not calculated correctly. The allocated buffer was smaller than what we expected. So WMI message corrupted skb_info, which is at the end of skb->data. This fix takes TLV header into account even if the element is zero-length. Crash log: [49.629986] Unhandled kernel unaligned access[#1]: [49.634932] CPU: 0 PID: 1176 Comm: logd Not tainted 4.4.60 #180 [49.641040] task: 83051460 ti: 8329c000 task.ti: 8329c000 [49.646608] $ 0 : 00000000 00000001 80984a80 00000000 [49.652038] $ 4 : 45259e89 8046d484 8046df30 8024ba70 [49.657468] $ 8 : 00000000 804cc4c0 00000001 20306320 [49.662898] $12 : 33322037 000110f2 00000000 31203930 [49.668327] $16 : 82792b40 80984a80 00000001 804207fc [49.673757] $20 : 00000000 0000012c 00000040 80470000 [49.679186] $24 : 00000000 8024af7c [49.684617] $28 : 8329c000 8329db88 00000001 802c58d0 [49.690046] Hi : 00000000 [49.693022] Lo : 453c0000 [49.696013] epc : 800efae4 put_page+0x0/0x58 [49.700615] ra : 802c58d0 skb_release_data+0x148/0x1d4 [49.706184] Status: 1000fc03 KERNEL EXL IE [49.710531] Cause : 00800010 (ExcCode 04) [49.714669] BadVA : 45259e89 [49.717644] PrId : 00019374 (MIPS 24Kc) Signed-off-by: Zhi Chen <zhichen@xxxxxxxxxxxxxx> Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx> Cc: Brian Norris <briannorris@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/wireless/ath/ath10k/wmi-tlv.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/drivers/net/wireless/ath/ath10k/wmi-tlv.c +++ b/drivers/net/wireless/ath/ath10k/wmi-tlv.c @@ -1486,10 +1486,10 @@ ath10k_wmi_tlv_op_gen_start_scan(struct bssid_len = arg->n_bssids * sizeof(struct wmi_mac_addr); ie_len = roundup(arg->ie_len, 4); len = (sizeof(*tlv) + sizeof(*cmd)) + - (arg->n_channels ? sizeof(*tlv) + chan_len : 0) + - (arg->n_ssids ? sizeof(*tlv) + ssid_len : 0) + - (arg->n_bssids ? sizeof(*tlv) + bssid_len : 0) + - (arg->ie_len ? sizeof(*tlv) + ie_len : 0); + sizeof(*tlv) + chan_len + + sizeof(*tlv) + ssid_len + + sizeof(*tlv) + bssid_len + + sizeof(*tlv) + ie_len; skb = ath10k_wmi_alloc_skb(ar, len); if (!skb)