ath10k: Fix kernel panic due to use after free

PATCH In review Karthikeyan Periyasamy 2 participants 3 messages Nov 9, 2018 – Dec 20, 2018 Qualcomm Atheros ATH10K wireless driver

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Karthikeyan Periyasamy

author

2018-11-09 08:55 UTC #0 lore raw

PATCH 1/1 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 <[email protected]>

---
 drivers/net/wireless/ath/ath10k/mac.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

drivers/net/wireless/ath/ath10k/mac.c +5 -5

index c5130fa..fbf4ff0 100644
@@ -6387,11 +6387,6 @@ 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,

@@ -6431,6 +6426,11 @@ 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]);

Signature · 1 line

1.9.1

Kalle Valo

2018-12-20 16:51 UTC #1 lore raw

Quoted 54 lines · Karthikeyan Periyasamy

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)

Quoted 8 lines

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 <[email protected]>
Signed-off-by Kalle Valo <[email protected]>

Patch applied to ath-next branch of ath.git, thanks.

553a7cca769d ath10k: fix kernel panic due to use after free

Signature · 3 lines

https://patchwork.kernel.org/patch/10675533/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

Kalle Valo

2018-12-20 16:51 UTC #2 lore raw

In reply to Karthikeyan Periyasamy

Quoted 54 lines · Karthikeyan Periyasamy

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)

Quoted 8 lines

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 <[email protected]>
Signed-off-by Kalle Valo <[email protected]>

Patch applied to ath-next branch of ath.git, thanks.

553a7cca769d ath10k: fix kernel panic due to use after free

Signature · 9 lines

https://patchwork.kernel.org/patch/10675533/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches


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