Message-ID: <2025022604-CVE-2022-49123-8a84@gregkh>
Date: Wed, 26 Feb 2025 02:55:28 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: CVE-2022-49123: ath11k: Fix frames flush failure caused by deadlock

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

ath11k: Fix frames flush failure caused by deadlock

We are seeing below warnings:

kernel: [25393.301506] ath11k_pci 0000:01:00.0: failed to flush mgmt transmit queue 0
kernel: [25398.421509] ath11k_pci 0000:01:00.0: failed to flush mgmt transmit queue 0
kernel: [25398.421831] ath11k_pci 0000:01:00.0: dropping mgmt frame for vdev 0, is_started 0

this means ath11k fails to flush mgmt. frames because wmi_mgmt_tx_work
has no chance to run in 5 seconds.

By setting /proc/sys/kernel/hung_task_timeout_secs to 20 and increasing
ATH11K_FLUSH_TIMEOUT to 50 we get below warnings:

kernel: [  120.763160] INFO: task wpa_supplicant:924 blocked for more than 20 seconds.
kernel: [  120.763169]       Not tainted 5.10.90 #12
kernel: [  120.763177] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kernel: [  120.763186] task:wpa_supplicant  state:D stack:    0 pid:  924 ppid:     1 flags:0x000043a0
kernel: [  120.763201] Call Trace:
kernel: [  120.763214]  __schedule+0x785/0x12fa
kernel: [  120.763224]  ? lockdep_hardirqs_on_prepare+0xe2/0x1bb
kernel: [  120.763242]  schedule+0x7e/0xa1
kernel: [  120.763253]  schedule_timeout+0x98/0xfe
kernel: [  120.763266]  ? run_local_timers+0x4a/0x4a
kernel: [  120.763291]  ath11k_mac_flush_tx_complete+0x197/0x2b1 [ath11k 13c3a9bf37790f4ac8103b3decf7ab4008ac314a]
kernel: [  120.763306]  ? init_wait_entry+0x2e/0x2e
kernel: [  120.763343]  __ieee80211_flush_queues+0x167/0x21f [mac80211 335da900954f1c5ea7f1613d92088ce83342042c]
kernel: [  120.763378]  __ieee80211_recalc_idle+0x105/0x125 [mac80211 335da900954f1c5ea7f1613d92088ce83342042c]
kernel: [  120.763411]  ieee80211_recalc_idle+0x14/0x27 [mac80211 335da900954f1c5ea7f1613d92088ce83342042c]
kernel: [  120.763441]  ieee80211_free_chanctx+0x77/0xa2 [mac80211 335da900954f1c5ea7f1613d92088ce83342042c]
kernel: [  120.763473]  __ieee80211_vif_release_channel+0x100/0x131 [mac80211 335da900954f1c5ea7f1613d92088ce83342042c]
kernel: [  120.763540]  ieee80211_vif_release_channel+0x66/0x81 [mac80211 335da900954f1c5ea7f1613d92088ce83342042c]
kernel: [  120.763572]  ieee80211_destroy_auth_data+0xa3/0xe6 [mac80211 335da900954f1c5ea7f1613d92088ce83342042c]
kernel: [  120.763612]  ieee80211_mgd_deauth+0x178/0x29b [mac80211 335da900954f1c5ea7f1613d92088ce83342042c]
kernel: [  120.763654]  cfg80211_mlme_deauth+0x1a8/0x22c [cfg80211 8945aa5bc2af5f6972336665d8ad6f9c191ad5be]
kernel: [  120.763697]  nl80211_deauthenticate+0xfa/0x123 [cfg80211 8945aa5bc2af5f6972336665d8ad6f9c191ad5be]
kernel: [  120.763715]  genl_rcv_msg+0x392/0x3c2
kernel: [  120.763750]  ? nl80211_associate+0x432/0x432 [cfg80211 8945aa5bc2af5f6972336665d8ad6f9c191ad5be]
kernel: [  120.763782]  ? nl80211_associate+0x432/0x432 [cfg80211 8945aa5bc2af5f6972336665d8ad6f9c191ad5be]
kernel: [  120.763802]  ? genl_rcv+0x36/0x36
kernel: [  120.763814]  netlink_rcv_skb+0x89/0xf7
kernel: [  120.763829]  genl_rcv+0x28/0x36
kernel: [  120.763840]  netlink_unicast+0x179/0x24b
kernel: [  120.763854]  netlink_sendmsg+0x393/0x401
kernel: [  120.763872]  sock_sendmsg+0x72/0x76
kernel: [  120.763886]  ____sys_sendmsg+0x170/0x1e6
kernel: [  120.763897]  ? copy_msghdr_from_user+0x7a/0xa2
kernel: [  120.763914]  ___sys_sendmsg+0x95/0xd1
kernel: [  120.763940]  __sys_sendmsg+0x85/0xbf
kernel: [  120.763956]  do_syscall_64+0x43/0x55
kernel: [  120.763966]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
kernel: [  120.763977] RIP: 0033:0x79089f3fcc83
kernel: [  120.763986] RSP: 002b:00007ffe604f0508 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
kernel: [  120.763997] RAX: ffffffffffffffda RBX: 000059b40e987690 RCX: 000079089f3fcc83
kernel: [  120.764006] RDX: 0000000000000000 RSI: 00007ffe604f0558 RDI: 0000000000000009
kernel: [  120.764014] RBP: 00007ffe604f0540 R08: 0000000000000004 R09: 0000000000400000
kernel: [  120.764023] R10: 00007ffe604f0638 R11: 0000000000000246 R12: 000059b40ea04980
kernel: [  120.764032] R13: 00007ffe604f0638 R14: 000059b40e98c360 R15: 00007ffe604f0558
...
kernel: [  120.765230] INFO: task kworker/u32:26:4239 blocked for more than 20 seconds.
kernel: [  120.765238]       Not tainted 5.10.90 #12
kernel: [  120.765245] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kernel: [  120.765253] task:kworker/u32:26  state:D stack:    0 pid: 4239 ppid:     2 flags:0x00004080
kernel: [  120.765284] Workqueue: phy0 ieee80211_iface_work [mac80211]
kernel: [  120.765295] Call Trace:
kernel: [  120.765306]  __schedule+0x785/0x12fa
kernel: [  120.765316]  ? find_held_lock+0x3d/0xb2
kernel: [  120.765331]  schedule+0x7e/0xa1
kernel: [  120.765340]  schedule_preempt_disabled+0x15/0x1e
kernel: [  120.765349]  __mutex_lock_common+0x561/0xc0d
kernel: [  120.765375]  ? ieee80211_sta_work+0x3e/0x1232 [mac80211 335da900954f1c5ea7f1613d92088ce83342042c]
kernel: [  120.765390]  mutex_lock_nested+0x20/0x26
kernel: [  120.765416]  ieee80211_sta_work+0x3e/0x1232 [mac80211 335da900954f1c5ea7f1613d92088ce83342042c]
kernel: [  120.765430]  ? skb_dequeue+0x54/0x5e
kernel: [  120.765456]  ? ieee80211_iface_work+0x7b/0x339 [mac80211 335da900954f1c5ea7f1613d92088ce83342042c]
kernel: [  120.765485]  process_one_work+0x270/0x504
kernel: [  120.765501]  worker_thread+0x215/0x376
kernel: [  120.765514]  kthread+0x159/0x168
kernel: [  120.765526]  ? pr_cont_work+0x5b/0x5b
kernel: [  120.765536]  ? kthread_blkcg+0x31/0x31
kernel: [  120.765550]  ret_from_fork+0x22/0x30
...
kernel: [  120.765867] Showing all locks held in the system:
...
kernel: [  120.766164] 5 locks held by wpa_supplicant/924:
kernel: [  120.766172]  #0: ffffffffb1e63eb0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x36
kernel: [  120.766197]  #1: ffffffffb1e5b1c8 (rtnl_mutex){+.+.}-{3:3}, at: nl80211_pre_doit+0x2a/0x15c [cfg80211]
kernel: [  120.766238]  #2: ffff99f08347cd08 (&wdev->mtx){+.+.}-{3:3}, at: nl80211_deauthenticate+0xde/0x123 [cfg80211]
kernel: [  120.766279]  #3: ffff99f09df12a48 (&local->mtx){+.+.}-{3:3}, at: ieee80211_destroy_auth_data+0x9b/0xe6 [mac80211]
kernel: [  120.766321]  #4: ffff99f09df12ce0 (&local->chanctx_mtx){+.+.}-{3:3}, at: ieee80211_vif_release_channel+0x5e/0x81 [mac80211]
...
kernel: [  120.766585] 3 locks held by kworker/u32:26/4239:
kernel: [  120.766593]  #0: ffff99f04458f948 ((wq_completion)phy0){+.+.}-{0:0}, at: process_one_work+0x19a/0x504
kernel: [  120.766621]  #1: ffffbad54b3cfe50 ((work_completion)(&sdata->work)){+.+.}-{0:0}, at: process_one_work+0x1c0/0x504
kernel: [  120.766649]  #2: ffff99f08347cd08 (&wdev->mtx){+.+.}-{3:3}, at: ieee80211_sta_work+0x3e/0x1232 [mac80211]

With above info the issue is clear: First wmi_mgmt_tx_work is inserted
to local->workqueue after sdata->work inserted, then wpa_supplicant
acquires wdev->mtx in nl80211_deauthenticate and finally calls
ath11k_mac_op_flush where it waits all mgmt. frames to be sent out by
wmi_mgmt_tx_work. Meanwhile, sdata->work is blocked by wdev->mtx in
ieee80211_sta_work, as a result wmi_mgmt_tx_work has no chance to run.

Change to use ab->workqueue instead of local->workqueue to fix this issue.

The Linux kernel CVE team has assigned CVE-2022-49123 to this issue.


Affected and fixed versions
===========================

	Fixed in 5.17.3 with commit 33e723dc054edfc94da90eecca3b72cb424ce4a3
	Fixed in 5.18 with commit 261b07519518bd14cb168b287b17e1d195f8d0c8

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2022-49123
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/net/wireless/ath/ath11k/mac.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/33e723dc054edfc94da90eecca3b72cb424ce4a3
	https://git.kernel.org/stable/c/261b07519518bd14cb168b287b17e1d195f8d0c8

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