🔍 CVE-2026-80997

7.5
CVSS Score
HIGH
2026-09-11
2026-10-19 09:17
✅ 완료

🇰🇷 한글 설명

Linux 커널의 IPA(IP Accelerator) 드라이버에서 런타임 재개(runtime resume) 과정 중 모뎀 TX 큐가 영구적으로 중단되는 취약점이 발견되었습니다. 전원 상태가 활성화되기 전에 큐 재개 작업이 실행되어 데이터 전송이 멈추고, 네트워크 워치독이 작동하지 않아 통신 기능이 마비됩니다.

💡 쉬운 설명

스마트폰의 모뎀이 절전 모드에서 깨어날 때, 데이터 전송 통로를 다시 열어주는 타이밍이 어긋나 통신이 끊기는 문제입니다. 이로 인해 셀룰러 데이터 사용이 불가능해지며 기기를 재부팅해야 할 수 있습니다.

🇺🇸 원문 (English)

In the Linux kernel, the following vulnerability has been resolved: net: ipa: fix stalled modem TX queue after runtime resume ipa_start_xmit() unconditionally stops the TX queue before calling pm_runtime_get(), relying on the wake scheduled by runtime resume (ipa_modem_wake_queue_work()) to restart it once power is ACTIVE. But that work is queued from within the runtime resume callback, before the device's power state reaches RPM_ACTIVE, so it can run while the device is still RPM_RESUMING. The wake is then consumed too early: the transmit it restarts stops the queue again, pm_runtime_get() returns -EINPROGRESS without arranging any future wake (deferred_resume exists only for RPM_SUSPENDING), and after the resume completes nothing is left to wake the queue. Transmit stalls permanently: packets pile up in the qdisc behind the stopped queue, the device runtime-suspends, and since the netdev registers no ndo_tx_timeout the watchdog never fires. Observed on SM7635 (Fairphone 6) as the cellular data path going permanently deaf within hours, RX included, since nothing resumes the suspended endpoints. Close the window by making the wake work wait for the resume to complete (pm_runtime_get_sync()) before waking the queue. Every queue stop is then guaranteed a later wake that happens while power is ACTIVE; a transmit racing a new suspend/resume cycle re-schedules the work. If the device could not be resumed, wake the queue anyway so pending packets are dropped by the transmit path rather than stranded. The STARTED power flag used to narrow this window: a wake running before the transmit path's stop suppressed that stop, but only once, as the flag was cleared by the first stop it absorbed. Removing the flag made a single transmit during an in-flight resume sufficient to strand the queue, which is the form observed. With an accelerated reproducer (autosuspend delay shortened to 5 ms, ~20 packets/s of TX), an unpatched kernel stalled three times in 230 s / 4380 packets; with this patch the same test ran 3601 s / 70298 packets without a stall.

📍 영향받는 시스템

Linux kernel (특히 SM7635/Fairphone 6 등 IPA를 사용하는 시스템)

⚔️ 공격 벡터

사용자의 직접적인 공격보다는 특정 전원 관리 시나리오(절전 모드 전환)에서 발생하는 논리적 오류에 의한 서비스 거부(DoS)

🛡️ 대응 방법

IPA 드라이버의 런타임 재개 로직을 수정하여 전원 상태가 완전히 활성화된 후 큐를 재개하도록 커널 패치 적용

🔧 검증 코드

출력된 커널 버전이 해당 취약점이 패치된 최신 보안 업데이트 버전인지 확인

Shell / Script
uname -r

📊 CVSS Vector String

CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

💻 영향받는 소프트웨어

Linux Kernel