🇰🇷 한글 설명
Linux 커널의 ath11k Wi-Fi 드라이버에서 발생한 취약점으로, 연결이 끊긴 상태에서 스캔을 실행할 때 peer_id가 0으로 초기화되어 유효성 검사를 통과하지 못하는 문제가 있습니다. 이는 특정 커밋에서 구조체를 초기화할 때 peer_id를 유효하지 않은 값(HAL_INVALID_PEERID)으로 설정하지 않아 발생한 논리적 오류입니다.
💡 쉬운 설명
Wi-Fi 연결이 끊겼을 때 시스템이 상대방의 식별 번호를 잘못 인식하여 오류 로그를 남기거나 비정상적인 동작을 할 수 있는 문제입니다. 데이터 초기화 과정에서 식별 번호를 '없음' 상태로 정확히 설정하지 않아 발생합니다.
🇺🇸 원문 (English)
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath11k: fix failed to find the peer with peer_id 0 when disconnected
It has a fail log which is ath11k_dbg in ath11k_dp_rx_process_mon_status(),
as below, it will not print when debug_mask is not set ATH11K_DBG_DATA.
ath11k_dbg(ab, ATH11K_DBG_DATA,
"failed to find the peer with peer_id %d\n",
ppdu_info.peer_id);
When run scan with station disconnected, the peer_id is 0 for case
HAL_RX_MPDU_START in ath11k_hal_rx_parse_mon_status_tlv() which called
from ath11k_dp_rx_process_mon_status(), and the peer_id of ppdu_info is
reset to 0 in the while loop, so it does not match condition of the
check "if (ppdu_info->peer_id == HAL_INVALID_PEERID" in the loop, and
then the log "failed to find the peer with peer_id 0" print after the
check in the loop, it is below call stack when debug_mask is set
ATH11K_DBG_DATA.
The reason is this commit 01d2f285e3e5 ("ath11k: decode HE status tlv")
add "memset(ppdu_info, 0, sizeof(struct hal_rx_mon_ppdu_info))" in
ath11k_dp_rx_process_mon_status(), but the commit does not initialize
the peer_id to HAL_INVALID_PEERID, then lead the check mis-match.
Callstack of the failed log:
[12335.689072] RIP: 0010:ath11k_dp_rx_process_mon_status+0x9ea/0x1020 [ath11k]
[12335.689157] Code: 89 ff e8 f9 10 00 00 be 01 00 00 00 4c 89 f7 e8 dc 4b 4e de 48 8b 85 38 ff ff ff c7 80 e4 07 00 00 01 00 00 00 e9 20 f8 ff ff <0f> 0b 41 0f b7 96 be 06 00 00 48 c7 c6 b8 50 44 c1 4c 89 ff e8 fd
[12335.689180] RSP: 0018:ffffb874001a4ca0 EFLAGS: 00010246
[12335.689210] RAX: 0000000000000000 RBX: ffff995642cbd100 RCX: 0000000000000000
[12335.689229] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff99564212cd18
[12335.689248] RBP: ffffb874001a4dc0 R08: 0000000000000001 R09: 0000000000000000
[12335.689268] R10: 0000000000000220 R11: ffffb874001a48e8 R12: ffff995642473d40
[12335.689286] R13: ffff99564212c5b8 R14: ffff9956424736a0 R15: ffff995642120000
[12335.689303] FS: 0000000000000000(0000) GS:ffff995739000000(0000) knlGS:0000000000000000
[12335.689323] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[12335.689341] CR2: 00007f43c5d5e039 CR3: 000000011c012005 CR4: 00000000000606e0
[12335.689360] Call Trace:
[12335.689377] <IRQ>
[12335.689418] ? rcu_read_lock_held_common+0x12/0x50
[12335.689447] ? rcu_read_lock_sched_held+0x25/0x80
[12335.689471] ? rcu_read_lock_held_common+0x12/0x50
[12335.689504] ath11k_dp_rx_process_mon_rings+0x8d/0x4f0 [ath11k]
[12335.689578] ? ath11k_dp_rx_process_mon_rings+0x8d/0x4f0 [ath11k]
[12335.689653] ? lock_acquire+0xef/0x360
[12335.689681] ? rcu_read_lock_sched_held+0x25/0x80
[12335.689713] ath11k_dp_service_mon_ring+0x38/0x60 [ath11k]
[12335.689784] ? ath11k_dp_rx_process_mon_rings+0x4f0/0x4f0 [ath11k]
[12335.689860] call_timer_fn+0xb2/0x2f0
[12335.689897] ? ath11k_dp_rx_process_mon_rings+0x4f0/0x4f0 [ath11k]
[12335.689970] run_timer_softirq+0x21f/0x540
[12335.689999] ? ktime_get+0xad/0x160
[12335.690025] ? lapic_next_deadline+0x2c/0x40
[12335.690053] ? clockevents_program_event+0x82/0x100
[12335.690093] __do_softirq+0x151/0x4a8
[12335.690135] irq_exit_rcu+0xc9/0x100
[12335.690165] sysvec_apic_timer_interrupt+0xa8/0xd0
[12335.690189] </IRQ>
[12335.690204] <TASK>
[12335.690225] asm_sysvec_apic_timer_interrupt+0x12/0x20
Reset the default value to HAL_INVALID_PEERID each time after memset
of ppdu_info as well as others memset which existed in function
ath11k_dp_rx_process_mon_status(), then the failed log disappeared.
Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3
📍 영향받는 시스템
Linux kernel with ath11k driver (specifically WCN6855 hardware environments)
⚔️ 공격 벡터
Disconnected station scan during monitor mode operation
🛡️ 대응 방법
Linux kernel을 업데이트하여 ath11k_dp_rx_process_mon_status() 함수 내에서 peer_id를 HAL_INVALID_PEERID로 올바르게 초기화하도록 패치 적용
🔧 검증 코드
커널 버전과 ath11k 모듈 정보를 확인하여 해당 취약점이 해결된 최신 패치 버전이 적용되었는지 확인합니다.
uname -r && modinfo ath11k | grep -i version