diff options
| author | Zhi Chen <zhichen@codeaurora.org> | 2018-12-20 15:24:43 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-26 11:32:43 +0300 |
| commit | dd619b90dd7164aa18119e7a55f7804f88ff63e7 (patch) | |
| tree | e682c2babef229d6877eb116807971e76f6fd211 | |
| parent | ca8ad9bcbebd03bf626074829eaaf67ee0e01899 (diff) | |
| download | linux-dd619b90dd7164aa18119e7a55f7804f88ff63e7.tar.xz | |
ath10k: fix peer stats null pointer dereference
[ Upstream commit 2d3b55853b123c177037cf534c5aaa2650310094 ]
There was a race condition in SMP that an ath10k_peer was created but its
member sta was null. Following are procedures of ath10k_peer creation and
member sta access in peer statistics path.
1. Peer creation:
ath10k_peer_create()
=>ath10k_wmi_peer_create()
=>ath10k_wait_for_peer_created()
...
# another kernel path, RX from firmware
ath10k_htt_t2h_msg_handler()
=>ath10k_peer_map_event()
=>wake_up()
# ar->peer_map[id] = peer //add peer to map
#wake up original path from waiting
...
# peer->sta = sta //sta assignment
2. RX path of statistics
ath10k_htt_t2h_msg_handler()
=>ath10k_update_per_peer_tx_stats()
=>ath10k_htt_fetch_peer_stats()
# peer->sta //sta accessing
Any access of peer->sta after peer was added to peer_map but before sta was
assigned could cause a null pointer issue. And because these two steps are
asynchronous, no proper lock can protect them. So both peer and sta need to
be checked before access.
Tested: QCA9984 with firmware ver 10.4-3.9.0.1-00005
Signed-off-by: Zhi Chen <zhichen@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/net/wireless/ath/ath10k/debugfs_sta.c | 2 | ||||
| -rw-r--r-- | drivers/net/wireless/ath/ath10k/htt_rx.c | 4 |
2 files changed, 3 insertions, 3 deletions
diff --git a/drivers/net/wireless/ath/ath10k/debugfs_sta.c b/drivers/net/wireless/ath/ath10k/debugfs_sta.c index a63c97e2c50c..6f10331e986b 100644 --- a/drivers/net/wireless/ath/ath10k/debugfs_sta.c +++ b/drivers/net/wireless/ath/ath10k/debugfs_sta.c @@ -71,7 +71,7 @@ void ath10k_sta_update_rx_tid_stats_ampdu(struct ath10k *ar, u16 peer_id, u8 tid spin_lock_bh(&ar->data_lock); peer = ath10k_peer_find_by_id(ar, peer_id); - if (!peer) + if (!peer || !peer->sta) goto out; arsta = (struct ath10k_sta *)peer->sta->drv_priv; diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c index 4d1cd90d6d27..03d4cc6f35bc 100644 --- a/drivers/net/wireless/ath/ath10k/htt_rx.c +++ b/drivers/net/wireless/ath/ath10k/htt_rx.c @@ -2589,7 +2589,7 @@ static void ath10k_htt_fetch_peer_stats(struct ath10k *ar, rcu_read_lock(); spin_lock_bh(&ar->data_lock); peer = ath10k_peer_find_by_id(ar, peer_id); - if (!peer) { + if (!peer || !peer->sta) { ath10k_warn(ar, "Invalid peer id %d peer stats buffer\n", peer_id); goto out; @@ -2642,7 +2642,7 @@ static void ath10k_fetch_10_2_tx_stats(struct ath10k *ar, u8 *data) rcu_read_lock(); spin_lock_bh(&ar->data_lock); peer = ath10k_peer_find_by_id(ar, peer_id); - if (!peer) { + if (!peer || !peer->sta) { ath10k_warn(ar, "Invalid peer id %d in peer stats buffer\n", peer_id); goto out; |