Return-path: Received: from mail-lf0-f43.google.com ([209.85.215.43]:35655 "EHLO mail-lf0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751522AbcKNNXt (ORCPT ); Mon, 14 Nov 2016 08:23:49 -0500 Received: by mail-lf0-f43.google.com with SMTP id b14so57966116lfg.2 for ; Mon, 14 Nov 2016 05:23:47 -0800 (PST) From: Michal Kazior To: ath10k@lists.infradead.org Cc: linux-wireless@vger.kernel.org, Michal Kazior Subject: [PATCH] ath10k: fix null deref on wmi-tlv when trying spectral scan Date: Mon, 14 Nov 2016 14:25:23 +0100 Message-Id: <1479129923-11083-1-git-send-email-michal.kazior@tieto.com> (sfid-20161114_142434_380890_F6A14A29) Sender: linux-wireless-owner@vger.kernel.org List-ID: 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] [] ? ath10k_spectral_scan_config+0x96/0x200 [ath10k_core] [ 168.104871] [] ? filemap_fault+0xb2/0x4a0 [ 168.106696] [] write_file_spec_scan_ctl+0x116/0x280 [ath10k_core] [ 168.109618] [] full_proxy_write+0x51/0x80 [ 168.111443] [] __vfs_write+0x28/0x120 [ 168.113090] [] ? security_file_permission+0x3d/0xc0 [ 168.114932] [] ? percpu_down_read+0x12/0x60 [ 168.116680] [] vfs_write+0xb8/0x1a0 [ 168.118293] [] SyS_write+0x46/0xa0 [ 168.119912] [] entry_SYSCALL_64_fastpath+0x1a/0xa4 [ 168.121737] Code: Bad RIP value. [ 168.123318] RIP [< (null)>] (null) Signed-off-by: Michal Kazior --- drivers/net/wireless/ath/ath10k/wmi-ops.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/wireless/ath/ath10k/wmi-ops.h b/drivers/net/wireless/ath/ath10k/wmi-ops.h index c9a8bb1186f2..c7956e181f80 100644 --- a/drivers/net/wireless/ath/ath10k/wmi-ops.h +++ b/drivers/net/wireless/ath/ath10k/wmi-ops.h @@ -660,6 +660,9 @@ ath10k_wmi_vdev_spectral_conf(struct ath10k *ar, struct sk_buff *skb; u32 cmd_id; + if (!ar->wmi.ops->gen_vdev_spectral_conf) + return -EOPNOTSUPP; + skb = ar->wmi.ops->gen_vdev_spectral_conf(ar, arg); if (IS_ERR(skb)) return PTR_ERR(skb); @@ -675,6 +678,9 @@ ath10k_wmi_vdev_spectral_enable(struct ath10k *ar, u32 vdev_id, u32 trigger, struct sk_buff *skb; u32 cmd_id; + if (!ar->wmi.ops->gen_vdev_spectral_enable) + return -EOPNOTSUPP; + skb = ar->wmi.ops->gen_vdev_spectral_enable(ar, vdev_id, trigger, enable); if (IS_ERR(skb)) -- 2.1.4