CVE-2022-49123 in Linux
Summary
by MITRE • 02/26/2025
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: 00007ffe604
---truncated---
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Analysis
by VulDB Data Team • 02/26/2025
The vulnerability CVE-2022-49123 affects the linux kernel's ath11k wireless driver, specifically addressing a deadlock condition that prevents proper flushing of management frames during wireless communication. This issue manifests when the driver fails to complete management transmit queue flushing within a 5-second timeout period, leading to frame drops and system instability. The problem originates from the wmi_mgmt_tx_work function which cannot execute due to the deadlock, causing the kernel to log warnings about failed flush operations and subsequently dropping management frames for virtual devices. The deadlock occurs in the ath11k_mac_flush_tx_complete function where the system becomes blocked while attempting to flush transmit queues, as evidenced by the hung task timeout messages showing wpa_supplicant blocked for over 20 seconds.
The technical flaw stems from improper synchronization mechanisms within the ath11k driver's management frame handling code, creating a scenario where the wmi_mgmt_tx_work workqueue item cannot be scheduled or executed in a timely manner. This condition is classified under CWE-362, which describes a race condition where concurrent processes or threads can cause system instability or denial of service. The issue impacts the mac80211 subsystem and cfg80211 interfaces that manage wireless network operations, particularly during authentication and channel release operations. When management frames cannot be flushed properly, the system enters a state where it cannot properly handle wireless network events, leading to potential disconnections and service degradation.
The operational impact of this vulnerability extends beyond simple performance degradation to potential complete wireless service disruption. Systems using affected ath11k drivers may experience intermittent wireless connectivity issues, failed authentication processes, and overall network instability. The deadlock condition can cause wpa_supplicant and other wireless management processes to become unresponsive, effectively disabling wireless functionality until the system is rebooted or the affected driver module is manually unloaded and reloaded. This vulnerability particularly affects devices using Qualcomm's QCA6174 and similar wireless chipsets that rely on the ath11k driver for network operations, creating a significant risk for enterprise and consumer devices relying on stable wireless connectivity.
Mitigation strategies should focus on implementing proper timeout handling and ensuring that workqueue items can execute without blocking critical system operations. The fix involves increasing the ATH11K_FLUSH_TIMEOUT value from its default to 50 seconds, allowing sufficient time for management frame processing while maintaining system responsiveness. Additionally, system administrators should monitor kernel logs for warnings about hung tasks and management frame flush failures, as these indicate potential occurrences of the vulnerability. The recommended approach includes upgrading to kernel versions that contain the specific fix for this deadlock condition, typically found in kernel versions 5.19 and later. Organizations should also consider implementing monitoring solutions that can detect the hung task warnings and automatically trigger driver reload procedures to maintain wireless service availability. The vulnerability demonstrates the importance of proper synchronization in kernel drivers and the potential for seemingly minor deadlock conditions to cause significant operational impacts in wireless networking infrastructure.