diff options
| author | Zhi Chen <zhichen@codeaurora.org> | 2018-12-20 14:24:43 +0200 |
|---|---|---|
| committer | Kalle Valo <kvalo@codeaurora.org> | 2018-12-20 19:08:35 +0200 |
| commit | 2d3b55853b123c177037cf534c5aaa2650310094 (patch) | |
| tree | b45f110447e035d3210707c717e440cdf1249366 /drivers/net/wireless/ath/ath10k/debugfs_sta.c | |
| parent | a3542d0c73cec6a45bde512ea2b43666c05a8c54 (diff) | |
ath10k: fix peer stats null pointer dereference
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>
Diffstat (limited to 'drivers/net/wireless/ath/ath10k/debugfs_sta.c')
| -rw-r--r-- | drivers/net/wireless/ath/ath10k/debugfs_sta.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/wireless/ath/ath10k/debugfs_sta.c b/drivers/net/wireless/ath/ath10k/debugfs_sta.c index 0f3fd65a459e..4778a455d81a 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; |