Remi Pommarel 581401cd3c wifi: ath9k: Fix possible stall on ath9k_txq_list_has_key()
[ Upstream commit 75086cc6dee046e3fbb3dba148b376d8802f83bc ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-27 08:43:40 +02:00
2023-07-27 08:43:36 +02:00
2023-07-27 08:43:35 +02:00
2023-04-05 11:23:43 +02:00
2020-10-17 11:18:18 -07:00
2023-06-21 15:45:38 +02:00
2023-07-24 19:09:12 +02:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
No description provided
Readme 5.7 GiB
Languages
C 97.6%
Assembly 1%
Shell 0.5%
Python 0.3%
Makefile 0.3%