diff options
| author | Remi Pommarel <repk@triplefau.lt> | 2023-06-09 11:37:44 +0200 |
|---|---|---|
| committer | Kalle Valo <quic_kvalo@quicinc.com> | 2023-06-13 12:09:12 +0300 |
| commit | 75086cc6dee046e3fbb3dba148b376d8802f83bc (patch) | |
| tree | 109acbc15eb5b9ab53866bd75f62c2c8ab1979ca | |
| parent | e2d1f005d3fbaea14ddea1a24db924406e55f6c3 (diff) | |
wifi: ath9k: Fix possible stall on ath9k_txq_list_has_key()
On EDMA capable hardware, ath9k_txq_list_has_key() can enter infinite
loop if it is called while all txq_fifos have packets that use different
key that the one we are looking for. Fix it by exiting the loop if all
txq_fifos have been checked already.
Because this loop is called under spin_lock_bh() (see ath_txq_lock) it
causes the following rcu stall:
rcu: INFO: rcu_sched self-detected stall on CPU
ath10k_pci 0000:01:00.0: failed to read temperature -11
rcu: 1-....: (5254 ticks this GP) idle=189/1/0x4000000000000002 softirq=8442983/8442984 fqs=2579
(t=5257 jiffies g=17983297 q=334)
Task dump for CPU 1:
task:hostapd state:R running task stack: 0 pid: 297 ppid: 289 flags:0x0000000a
Call trace:
dump_backtrace+0x0/0x170
show_stack+0x1c/0x24
sched_show_task+0x140/0x170
dump_cpu_task+0x48/0x54
rcu_dump_cpu_stacks+0xf0/0x134
rcu_sched_clock_irq+0x8d8/0x9fc
update_process_times+0xa0/0xec
tick_sched_timer+0x5c/0xd0
__hrtimer_run_queues+0x154/0x320
hrtimer_interrupt+0x120/0x2f0
arch_timer_handler_virt+0x38/0x44
handle_percpu_devid_irq+0x9c/0x1e0
handle_domain_irq+0x64/0x90
gic_handle_irq+0x78/0xb0
call_on_irq_stack+0x28/0x38
do_interrupt_handler+0x54/0x5c
el1_interrupt+0x2c/0x4c
el1h_64_irq_handler+0x14/0x1c
el1h_64_irq+0x74/0x78
ath9k_txq_has_key+0x1bc/0x250 [ath9k]
ath9k_set_key+0x1cc/0x3dc [ath9k]
drv_set_key+0x78/0x170
ieee80211_key_replace+0x564/0x6cc
ieee80211_key_link+0x174/0x220
ieee80211_add_key+0x11c/0x300
nl80211_new_key+0x12c/0x330
genl_family_rcv_msg_doit+0xbc/0x11c
genl_rcv_msg+0xd8/0x1c4
netlink_rcv_skb+0x40/0x100
genl_rcv+0x3c/0x50
netlink_unicast+0x1ec/0x2c0
netlink_sendmsg+0x198/0x3c0
____sys_sendmsg+0x210/0x250
___sys_sendmsg+0x78/0xc4
__sys_sendmsg+0x4c/0x90
__arm64_sys_sendmsg+0x28/0x30
invoke_syscall.constprop.0+0x60/0x100
do_el0_svc+0x48/0xd0
el0_svc+0x14/0x50
el0t_64_sync_handler+0xa8/0xb0
el0t_64_sync+0x158/0x15c
This rcu stall is hard to reproduce as is, but changing ATH_TXFIFO_DEPTH
from 8 to 2 makes it reasonably easy to reproduce.
Fixes: ca2848022c12 ("ath9k: Postpone key cache entry deletion for TXQ frames reference it")
Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Tested-by: Nicolas Escande <nico.escande@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230609093744.1985-1-repk@triplefau.lt
| -rw-r--r-- | drivers/net/wireless/ath/ath9k/main.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c index a4197c14f0a9..7f9f06ea8a05 100644 --- a/drivers/net/wireless/ath/ath9k/main.c +++ b/drivers/net/wireless/ath/ath9k/main.c @@ -850,7 +850,7 @@ static bool ath9k_txq_list_has_key(struct list_head *txq_list, u32 keyix) static bool ath9k_txq_has_key(struct ath_softc *sc, u32 keyix) { struct ath_hw *ah = sc->sc_ah; - int i; + int i, j; struct ath_txq *txq; bool key_in_use = false; @@ -868,8 +868,9 @@ static bool ath9k_txq_has_key(struct ath_softc *sc, u32 keyix) if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) { int idx = txq->txq_tailidx; - while (!key_in_use && - !list_empty(&txq->txq_fifo[idx])) { + for (j = 0; !key_in_use && + !list_empty(&txq->txq_fifo[idx]) && + j < ATH_TXFIFO_DEPTH; j++) { key_in_use = ath9k_txq_list_has_key( &txq->txq_fifo[idx], keyix); INCR(idx, ATH_TXFIFO_DEPTH); |