🇰🇷 한글 설명
Linux 커널의 ath11k 드라이버에서 QCA6390 및 WCN6855 칩셋 사용 시 발생하는 Use-After-Free 취약점입니다. 특정 커밋의 오류로 인해 피어 삭제 작업이 누락되어 dangling pointer가 발생하며, 이로 인해 시스템 크래시나 메모리 오류가 유발될 수 있습니다.
💡 쉬운 설명
무선 랜 카드가 연결을 끊을 때 메모리를 제대로 정리하지 못해 발생하는 오류입니다. 이로 인해 컴퓨터 시스템이 갑자기 멈추거나 불안정해질 수 있습니다.
🇺🇸 원문 (English)
In the Linux kernel, the following vulnerability has been resolved:
ath11k: free peer for station when disconnect from AP for QCA6390/WCN6855
Commit b4a0f54156ac ("ath11k: move peer delete after vdev stop of station
for QCA6390 and WCN6855") is to fix firmware crash by changing the WMI
command sequence, but actually skip all the peer delete operation, then
it lead commit 58595c9874c6 ("ath11k: Fixing dangling pointer issue upon
peer delete failure") not take effect, and then happened a use-after-free
warning from KASAN. because the peer->sta is not set to NULL and then used
later.
Change to only skip the WMI_PEER_DELETE_CMDID for QCA6390/WCN6855.
log of user-after-free:
[ 534.888665] BUG: KASAN: use-after-free in ath11k_dp_rx_update_peer_stats+0x912/0xc10 [ath11k]
[ 534.888696] Read of size 8 at addr ffff8881396bb1b8 by task rtcwake/2860
[ 534.888705] CPU: 4 PID: 2860 Comm: rtcwake Kdump: loaded Tainted: G W 5.15.0-wt-ath+ #523
[ 534.888712] Hardware name: Intel(R) Client Systems NUC8i7HVK/NUC8i7HVB, BIOS HNKBLi70.86A.0067.2021.0528.1339 05/28/2021
[ 534.888716] Call Trace:
[ 534.888720] <IRQ>
[ 534.888726] dump_stack_lvl+0x57/0x7d
[ 534.888736] print_address_description.constprop.0+0x1f/0x170
[ 534.888745] ? ath11k_dp_rx_update_peer_stats+0x912/0xc10 [ath11k]
[ 534.888771] kasan_report.cold+0x83/0xdf
[ 534.888783] ? ath11k_dp_rx_update_peer_stats+0x912/0xc10 [ath11k]
[ 534.888810] ath11k_dp_rx_update_peer_stats+0x912/0xc10 [ath11k]
[ 534.888840] ath11k_dp_rx_process_mon_status+0x529/0xa70 [ath11k]
[ 534.888874] ? ath11k_dp_rx_mon_status_bufs_replenish+0x3f0/0x3f0 [ath11k]
[ 534.888897] ? check_prev_add+0x20f0/0x20f0
[ 534.888922] ? __lock_acquire+0xb72/0x1870
[ 534.888937] ? find_held_lock+0x33/0x110
[ 534.888954] ath11k_dp_rx_process_mon_rings+0x297/0x520 [ath11k]
[ 534.888981] ? rcu_read_unlock+0x40/0x40
[ 534.888990] ? ath11k_dp_rx_pdev_alloc+0xd90/0xd90 [ath11k]
[ 534.889026] ath11k_dp_service_mon_ring+0x67/0xe0 [ath11k]
[ 534.889053] ? ath11k_dp_rx_process_mon_rings+0x520/0x520 [ath11k]
[ 534.889075] call_timer_fn+0x167/0x4a0
[ 534.889084] ? add_timer_on+0x3b0/0x3b0
[ 534.889103] ? lockdep_hardirqs_on_prepare.part.0+0x18c/0x370
[ 534.889117] __run_timers.part.0+0x539/0x8b0
[ 534.889123] ? ath11k_dp_rx_process_mon_rings+0x520/0x520 [ath11k]
[ 534.889157] ? call_timer_fn+0x4a0/0x4a0
[ 534.889164] ? mark_lock_irq+0x1c30/0x1c30
[ 534.889173] ? clockevents_program_event+0xdd/0x280
[ 534.889189] ? mark_held_locks+0xa5/0xe0
[ 534.889203] run_timer_softirq+0x97/0x180
[ 534.889213] __do_softirq+0x276/0x86a
[ 534.889230] __irq_exit_rcu+0x11c/0x180
[ 534.889238] irq_exit_rcu+0x5/0x20
[ 534.889244] sysvec_apic_timer_interrupt+0x8e/0xc0
[ 534.889251] </IRQ>
[ 534.889254] <TASK>
[ 534.889259] asm_sysvec_apic_timer_interrupt+0x12/0x20
[ 534.889265] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70
[ 534.889271] Code: 74 24 10 e8 ea c2 bf fd 48 89 ef e8 12 53 c0 fd 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 <e8> 13 a7 b5 fd 65 8b 05 cc d9 9c 5e 85 c0 74 0a 5b 5d c3 e8 a0 ee
[ 534.889276] RSP: 0018:ffffc90002e5f880 EFLAGS: 00000206
[ 534.889284] RAX: 0000000000000006 RBX: 0000000000000200 RCX: ffffffff9f256f10
[ 534.889289] RDX: 0000000000000000 RSI: ffffffffa1c6e420 RDI: 0000000000000001
[ 534.889293] RBP: ffff8881095e6200 R08: 0000000000000001 R09: ffffffffa40d2b8f
[ 534.889298] R10: fffffbfff481a571 R11: 0000000000000001 R12: ffff8881095e6e68
[ 534.889302] R13: ffffc90002e5f908 R14: 0000000000000246 R15: 0000000000000000
[ 534.889316] ? mark_lock+0xd0/0x14a0
[ 534.889332] klist_next+0x1d4/0x450
[ 534.889340] ? dpm_wait_for_subordinate+0x2d0/0x2d0
[ 534.889350] device_for_each_child+0xa8/0x140
[ 534.889360] ? device_remove_class_symlinks+0x1b0/0x1b0
[ 534.889370] ? __lock_release+0x4bd/0x9f0
[ 534.889378] ? dpm_suspend+0x26b/0x3f0
[ 534.889390] dpm_wait_for_subordinate+
---truncated---
📍 영향받는 시스템
Linux kernel (ath11k driver) using QCA6390 or WCN6855 chipsets
⚔️ 공격 벡터
Local/Remote (Wireless disconnection sequence manipulation)
🛡️ 대응 방법
Linux kernel을 최신 보안 패치가 적용된 버전으로 업데이트하십시오.
🔧 검증 코드
출력된 커널 버전이 취약점이 해결된 패치 이후 버전인지 확인하십시오.