From ebaa4b1620bf69f2bc43cb45ea85fbafdaec23c3 Mon Sep 17 00:00:00 2001 From: Vasanthakumar Thiagarajan Date: Mon, 10 Oct 2016 19:51:18 +0530 Subject: [PATCH] ath10k: fix kernel panic due to race in accessing arvif list arvifs list is traversed within data_lock spin_lock in tasklet context to fill channel information from the corresponding vif. This means any access to arvifs list for add/del operations should also be protected with the same spin_lock to avoid the race. Fix this by performing list add/del on arvfis within the data_lock. This could fix kernel panic something like the below. LR is at ath10k_htt_rx_pktlog_completion_handler+0x100/0xb6c [ath10k_core] PC is at ath10k_htt_rx_pktlog_completion_handler+0x1c0/0xb6c [ath10k_core] Internal error: Oops: 17 [#1] PREEMPT SMP ARM [] (ath10k_htt_rx_pktlog_completion_handler+0x2f4/0xb6c [ath10k_core]) [] (ath10k_htt_txrx_compl_task+0x8b4/0x1188 [ath10k_core]) [] (tasklet_action+0x8c/0xec) [] (__do_softirq+0xdc/0x208) [] (irq_exit+0x84/0xe0) [] (__handle_domain_irq+0x80/0xa0) [] (gic_handle_irq+0x38/0x5c) [] (__irq_svc+0x40/0x74) (gdb) list *(ath10k_htt_rx_pktlog_completion_handler+0x1c0) 0x136c0 is in ath10k_htt_rx_h_channel (drivers/net/wireless/ath/ath10k/htt_rx.c:769) 764 struct cfg80211_chan_def def; 765 766 lockdep_assert_held(&ar->data_lock); 767 768 list_for_each_entry(arvif, &ar->arvifs, list) { 769 if (arvif->vdev_id == vdev_id && 770 ath10k_mac_vif_chan(arvif->vif, &def) == 0) 771 return def.chan; 772 } 773 Signed-off-by: Vasanthakumar Thiagarajan Signed-off-by: Kalle Valo --- drivers/net/wireless/ath/ath10k/mac.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c index 2e5d2ca6d816..691b7b58c584 100644 --- a/drivers/net/wireless/ath/ath10k/mac.c +++ b/drivers/net/wireless/ath/ath10k/mac.c @@ -4931,7 +4931,9 @@ static int ath10k_add_interface(struct ieee80211_hw *hw, } ar->free_vdev_map &= ~(1LL << arvif->vdev_id); + spin_lock_bh(&ar->data_lock); list_add(&arvif->list, &ar->arvifs); + spin_unlock_bh(&ar->data_lock); /* It makes no sense to have firmware do keepalives. mac80211 already * takes care of this with idle connection polling. @@ -5082,7 +5084,9 @@ err_peer_delete: err_vdev_delete: ath10k_wmi_vdev_delete(ar, arvif->vdev_id); ar->free_vdev_map |= 1LL << arvif->vdev_id; + spin_lock_bh(&ar->data_lock); list_del(&arvif->list); + spin_unlock_bh(&ar->data_lock); err: if (arvif->beacon_buf) { @@ -5128,7 +5132,9 @@ static void ath10k_remove_interface(struct ieee80211_hw *hw, arvif->vdev_id, ret); ar->free_vdev_map |= 1LL << arvif->vdev_id; + spin_lock_bh(&ar->data_lock); list_del(&arvif->list); + spin_unlock_bh(&ar->data_lock); if (arvif->vdev_type == WMI_VDEV_TYPE_AP || arvif->vdev_type == WMI_VDEV_TYPE_IBSS) { -- 2.39.5