From 40bea976c72b9ee60f8d097852deb53ccbeaffbe Mon Sep 17 00:00:00 2001 From: Miaoqing Pan Date: Wed, 16 Nov 2016 17:23:08 +0800 Subject: [PATCH] ath9k: fix NULL pointer dereference relay_open() may return NULL, check the return value to avoid the crash. BUG: unable to handle kernel NULL pointer dereference at 0000000000000040 IP: [] ath_cmn_process_fft+0xd5/0x700 [ath9k_common] PGD 41cf28067 PUD 41be92067 PMD 0 Oops: 0000 [#1] SMP CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.8.6+ #35 Hardware name: Hewlett-Packard h8-1080t/2A86, BIOS 6.15 07/04/2011 task: ffffffff81e0c4c0 task.stack: ffffffff81e00000 RIP: 0010:[] [] ath_cmn_process_fft+0xd5/0x700 [ath9k_common] RSP: 0018:ffff88041f203ca0 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 000000000000059f RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffffffff81f0ca98 RBP: ffff88041f203dc8 R08: ffffffffffffffff R09: 00000000000000ff R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff81f0ca98 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88041f200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000040 CR3: 000000041b6ec000 CR4: 00000000000006f0 Stack: 0000000000000363 00000000000003f3 00000000000003f3 00000000000001f9 000000000000049a 0000000001252c04 ffff88041f203e44 ffff880417b4bfd0 0000000000000008 ffff88041785b9c0 0000000000000002 ffff88041613dc60 Call Trace: [] ath9k_tasklet+0x1b1/0x220 [ath9k] [] tasklet_action+0x4d/0xf0 [] __do_softirq+0x92/0x2a0 Reported-by: Devin Tuchsen Tested-by: Devin Tuchsen Signed-off-by: Miaoqing Pan Signed-off-by: Kalle Valo --- drivers/net/wireless/ath/ath9k/common-spectral.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/ath9k/common-spectral.c b/drivers/net/wireless/ath/ath9k/common-spectral.c index e2512d5bc0e1..eedf86b67cf5 100644 --- a/drivers/net/wireless/ath/ath9k/common-spectral.c +++ b/drivers/net/wireless/ath/ath9k/common-spectral.c @@ -528,6 +528,9 @@ int ath_cmn_process_fft(struct ath_spec_scan_priv *spec_priv, struct ieee80211_h if (!(radar_info->pulse_bw_info & SPECTRAL_SCAN_BITMASK)) return 0; + if (!spec_priv->rfs_chan_spec_scan) + return 1; + /* Output buffers are full, no need to process anything * since there is no space to put the result anyway */ @@ -1072,7 +1075,7 @@ static struct rchan_callbacks rfs_spec_scan_cb = { void ath9k_cmn_spectral_deinit_debug(struct ath_spec_scan_priv *spec_priv) { - if (IS_ENABLED(CONFIG_ATH9K_DEBUGFS)) { + if (IS_ENABLED(CONFIG_ATH9K_DEBUGFS) && spec_priv->rfs_chan_spec_scan) { relay_close(spec_priv->rfs_chan_spec_scan); spec_priv->rfs_chan_spec_scan = NULL; } @@ -1086,6 +1089,9 @@ void ath9k_cmn_spectral_init_debug(struct ath_spec_scan_priv *spec_priv, debugfs_phy, 1024, 256, &rfs_spec_scan_cb, NULL); + if (!spec_priv->rfs_chan_spec_scan) + return; + debugfs_create_file("spectral_scan_ctl", S_IRUSR | S_IWUSR, debugfs_phy, spec_priv, -- 2.30.2