From 3cb209f435233f2cc3397886358c772c082f62e3 Mon Sep 17 00:00:00 2001 From: Sara Sharon Date: Thu, 8 Oct 2020 18:12:42 +0300 Subject: [PATCH] iwlwifi: mvm: fix suspicious rcu usage warnings mvm mutex isn't held by iwl_mvm_set_aes_rx_seq or it caller. iee80211_local->key_mtx is held, but that is internal to mac80211. The same applies to iwl_mvm_wowlan_program_keys. Just hold rcu_read_lock, even though we are protected, the penalty isn't that bad. Warnings fixed are: [ 4143.788196] WARNING: suspicious RCU usage [ 4143.788211] ----------------------------- [ 4143.788220] suspicious rcu_dereference_protected() usage! [ 4143.788227] [ 4143.788234] rcu_scheduler_active = 2, debug_locks = 1 [ 4143.788242] 5 locks held by kworker/u8:9/5921: [ 4143.788331] #4: ffff88804e69ad08 (&local->key_mtx){+.+.}, at ie80211_iter_keys+0x46/0x380 [mac80211] [ 4143.788441] [ 4143.788441] Call Trace: [ 4143.788455] dump_stack+0xc1/0x11a [ 4143.788471] lockdep_rcu_suspicious+0x14a/0x153 [ 4143.788515] iwl_mvm_set_aes_rx_seq+0x4a9/0x570 [iwlmvm] [ 4143.788657] iwl_mvm_d3_update_keys+0x2ac/0x600 [iwlmvm] [ 4143.788784] ieee80211_iter_keys+0x10e/0x380 [mac80211] [ 4143.788838] iwl_mvm_setup_connection_keep+0x287/0x8d0 [iwlmvm] [ 7243.206556] WARNING: suspicious RCU usage [ 7243.206811] ----------------------------- [ 7243.206926] /suspicious rcu_dereference_protected() usage! [ 7243.207086] [ 7243.207204] rcu_scheduler_active = 2, debug_locks = 1 [ 7243.207321] 2 locks held by cat/15952: [ 7243.207564] #1: ffff888008c8ad08 (&local->key_mtx){+.+.}, at: ieee80211_iter_keys+0x46/0x380 [mac80211] [ 7243.207751] [ 7243.208094] Call Trace: [ 7243.208211] dump_stack+0xc1/0x11a [ 7243.208355] lockdep_rcu_suspicious+0x14a/0x153 [ 7243.208509] iwl_mvm_wowlan_program_keys+0x1db7/0x2340 [iwlmvm] [ 7243.209852] ieee80211_iter_keys+0x10e/0x380 [mac80211] Signed-off-by: Sara Sharon Signed-off-by: Luca Coelho Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/iwlwifi.20201008181047.65872d5f1670.I0b2fb2a65904ae686c3c7c05f881a1e3634dc900@changeid --- drivers/net/wireless/intel/iwlwifi/mvm/d3.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/d3.c b/drivers/net/wireless/intel/iwlwifi/mvm/d3.c index 9987172a9e013..d21143495e70b 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/d3.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/d3.c @@ -344,11 +344,12 @@ static void iwl_mvm_wowlan_program_keys(struct ieee80211_hw *hw, const u8 *pn; mvmsta = iwl_mvm_sta_from_mac80211(sta); - ptk_pn = rcu_dereference_protected( - mvmsta->ptk_pn[key->keyidx], - lockdep_is_held(&mvm->mutex)); - if (WARN_ON(!ptk_pn)) + rcu_read_lock(); + ptk_pn = rcu_dereference(mvmsta->ptk_pn[key->keyidx]); + if (WARN_ON(!ptk_pn)) { + rcu_read_unlock(); break; + } for (i = 0; i < IWL_MAX_TID_COUNT; i++) { pn = iwl_mvm_find_max_pn(key, ptk_pn, &seq, i, @@ -360,6 +361,8 @@ static void iwl_mvm_wowlan_program_keys(struct ieee80211_hw *hw, ((u64)pn[1] << 32) | ((u64)pn[0] << 40)); } + + rcu_read_unlock(); } else { for (i = 0; i < IWL_NUM_RSC; i++) { u8 *pn = seq.ccmp.pn; @@ -1363,10 +1366,12 @@ static void iwl_mvm_set_aes_rx_seq(struct iwl_mvm *mvm, struct aes_sc *scs, mvmsta = iwl_mvm_sta_from_mac80211(sta); - ptk_pn = rcu_dereference_protected(mvmsta->ptk_pn[key->keyidx], - lockdep_is_held(&mvm->mutex)); - if (WARN_ON(!ptk_pn)) + rcu_read_lock(); + ptk_pn = rcu_dereference(mvmsta->ptk_pn[key->keyidx]); + if (WARN_ON(!ptk_pn)) { + rcu_read_unlock(); return; + } for (tid = 0; tid < IWL_MAX_TID_COUNT; tid++) { struct ieee80211_key_seq seq = {}; @@ -1378,6 +1383,7 @@ static void iwl_mvm_set_aes_rx_seq(struct iwl_mvm *mvm, struct aes_sc *scs, memcpy(ptk_pn->q[i].pn[tid], seq.ccmp.pn, IEEE80211_CCMP_PN_LEN); } + rcu_read_unlock(); } else { for (tid = 0; tid < IWL_NUM_RSC; tid++) { struct ieee80211_key_seq seq = {}; -- 2.39.5