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author | Karthikeyan Periyasamy <periyasa@codeaurora.org> | 2018-12-20 09:53:17 +0200 |
---|---|---|
committer | Kalle Valo <kvalo@codeaurora.org> | 2018-12-20 18:49:48 +0200 |
commit | 553a7cca769d551f1317186760631487c47e23bf (patch) | |
tree | 56ffa22c07622d29dd87e1821b9b497ac79980b4 /drivers/net/wireless | |
parent | bff70e5f78e9708de18cbed003abe10349719ba5 (diff) | |
download | linux-553a7cca769d551f1317186760631487c47e23bf.tar.bz2 |
ath10k: fix kernel panic due to use after free
This issue arise in a race condition between ath10k_sta_state() and
ath10k_htt_fetch_peer_stats(), explained in below scenario
Steps:
1. In ath10k_sta_state(), arsta->tx_stats get deallocated before peer deletion
when the station moves from IEEE80211_STA_NONE to IEEE80211_STA_NOTEXIST
state.
2. Meanwhile ath10k receive HTT_T2H_MSG_TYPE_PEER_STATS message.
In ath10k_htt_fetch_peer_stats(), arsta->tx_stats get accessed after
the peer validation check.
Since arsta->tx_stats get freed before the peer deletion [1].
ath10k_htt_fetch_peer_stats() ended up in "use after free" situation.
Fixed this issue by moving the arsta->tx_stats free handling after the
peer deletion. so that ath10k_htt_fetch_peer_stats() will not end up in
"use after free" situation.
Kernel Panic:
Unable to handle kernel NULL pointer dereference at virtual address 00000286
pgd = d8754000
[00000286] *pgd=00000000
Internal error: Oops: 5 [#1] PREEMPT SMP ARM
...
CPU: 0 PID: 6245 Comm: hostapd Not tainted
task: dc44cac0 ti: d4a38000 task.ti: d4a38000
PC is at kmem_cache_alloc+0x7c/0x114
LR is at ath10k_sta_state+0x190/0xd58 [ath10k_core]
pc : [<c02bdc50>] lr : [<bf916b78>] psr: 20000013
sp : d4a39b88 ip : 00000000 fp : 00000001
r10: 00000000 r9 : 1d3bc000 r8 : 00000dc0
r7 : 000080d0 r6 : d4a38000 r5 : dd401b00 r4 : 00000286
r3 : 00000000 r2 : d4a39ba0 r1 : 000080d0 r0 : dd401b00
Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
Control: 10c5787d Table: 5a75406a DAC: 00000015
Process hostapd (pid: 6245, stack limit = 0xd4a38238)
Stack: (0xd4a39b88 to 0xd4a3a000)
...
[<c02bdc50>] (kmem_cache_alloc) from [<bf916b78>] (ath10k_sta_state+0x190/0xd58 [ath10k_core])
[<bf916b78>] (ath10k_sta_state [ath10k_core]) from [<bf870d4c>] (sta_info_insert_rcu+0x418/0x61c [mac80211])
[<bf870d4c>] (sta_info_insert_rcu [mac80211]) from [<bf88634c>] (ieee80211_add_station+0xf0/0x134 [mac80211])
[<bf88634c>] (ieee80211_add_station [mac80211]) from [<bf83f3c4>] (nl80211_new_station+0x330/0x36c [cfg80211])
[<bf83f3c4>] (nl80211_new_station [cfg80211]) from [<bf6c4040>] (extack_doit+0x2c/0x74 [compat])
[<bf6c4040>] (extack_doit [compat]) from [<c05c285c>] (genl_rcv_msg+0x274/0x30c)
[<c05c285c>] (genl_rcv_msg) from [<c05c1d98>] (netlink_rcv_skb+0x58/0xac)
[<c05c1d98>] (netlink_rcv_skb) from [<c05c25d4>] (genl_rcv+0x20/0x34)
[<c05c25d4>] (genl_rcv) from [<c05c1750>] (netlink_unicast+0x11c/0x204)
[<c05c1750>] (netlink_unicast) from [<c05c1be0>] (netlink_sendmsg+0x30c/0x370)
[<c05c1be0>] (netlink_sendmsg) from [<c0587e90>] (sock_sendmsg+0x70/0x84)
[<c0587e90>] (sock_sendmsg) from [<c058970c>] (___sys_sendmsg.part.3+0x188/0x228)
[<c058970c>] (___sys_sendmsg.part.3) from [<c058a594>] (__sys_sendmsg+0x4c/0x70)
[<c058a594>] (__sys_sendmsg) from [<c0208c80>] (ret_fast_syscall+0x0/0x44)
Code: ebfffec1 e1a04000 ea00001b e5953014 (e7940003)
ath10k_pci 0000:01:00.0: SWBA overrun on vdev 0, skipped old beacon
Hardware tested: QCA9984
Firmware tested: 10.4-3.6.0.1-00004
Fixes: a904417fc ("ath10k: add extended per sta tx statistics support")
Signed-off-by: Karthikeyan Periyasamy <periyasa@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Diffstat (limited to 'drivers/net/wireless')
-rw-r--r-- | drivers/net/wireless/ath/ath10k/mac.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c index 9d75de7b633b..3d539450f6c5 100644 --- a/drivers/net/wireless/ath/ath10k/mac.c +++ b/drivers/net/wireless/ath/ath10k/mac.c @@ -6361,11 +6361,6 @@ static int ath10k_sta_state(struct ieee80211_hw *hw, "mac vdev %d peer delete %pM sta %pK (sta gone)\n", arvif->vdev_id, sta->addr, sta); - if (ath10k_debug_is_extd_tx_stats_enabled(ar)) { - kfree(arsta->tx_stats); - arsta->tx_stats = NULL; - } - if (sta->tdls) { ret = ath10k_mac_tdls_peer_update(ar, arvif->vdev_id, sta, @@ -6405,6 +6400,11 @@ static int ath10k_sta_state(struct ieee80211_hw *hw, } spin_unlock_bh(&ar->data_lock); + if (ath10k_debug_is_extd_tx_stats_enabled(ar)) { + kfree(arsta->tx_stats); + arsta->tx_stats = NULL; + } + for (i = 0; i < ARRAY_SIZE(sta->txq); i++) ath10k_mac_txq_unref(ar, sta->txq[i]); |