🔍 CVE-2024-26937

5.5
CVSS Score
MEDIUM
2024-05-01
2026-10-15 01:17
✅ 완료

🇰🇷 한글 설명

Linux 커널의 Intel i915 GPU 드라이버에서 preempt-to-busy 레이스 컨디션으로 인해 queue_priority_hint가 제대로 초기화되지 않는 버그. 엔진 parking 시점에 커널 panic (GEM_BUG_ON)이 발생할 수 있습니다.

💡 쉬운 설명

Intel GPU 드라이버의 작업 스케줄링 버그로, GPU가 유휴 상태로 전환될 때 시스템이 충돌할 수 있습니다. 로컬 공격자가 특정 GPU 작업 패턴을 유발하여 시스템 가용성을 침해할 수 있습니다.

🇺🇸 원문 (English)

In the Linux kernel, the following vulnerability has been resolved: drm/i915/gt: Reset queue_priority_hint on parking Originally, with strict in order execution, we could complete execution only when the queue was empty. Preempt-to-busy allows replacement of an active request that may complete before the preemption is processed by HW. If that happens, the request is retired from the queue, but the queue_priority_hint remains set, preventing direct submission until after the next CS interrupt is processed. This preempt-to-busy race can be triggered by the heartbeat, which will also act as the power-management barrier and upon completion allow us to idle the HW. We may process the completion of the heartbeat, and begin parking the engine before the CS event that restores the queue_priority_hint, causing us to fail the assertion that it is MIN. <3>[ 166.210729] __engine_park:283 GEM_BUG_ON(engine->sched_engine->queue_priority_hint != (-((int)(~0U >> 1)) - 1)) <0>[ 166.210781] Dumping ftrace buffer: <0>[ 166.210795] --------------------------------- ... <0>[ 167.302811] drm_fdin-1097 2..s1. 165741070us : trace_ports: 0000:00:02.0 rcs0: promote { ccid:20 1217:2 prio 0 } <0>[ 167.302861] drm_fdin-1097 2d.s2. 165741072us : execlists_submission_tasklet: 0000:00:02.0 rcs0: preempting last=1217:2, prio=0, hint=2147483646 <0>[ 167.302928] drm_fdin-1097 2d.s2. 165741072us : __i915_request_unsubmit: 0000:00:02.0 rcs0: fence 1217:2, current 0 <0>[ 167.302992] drm_fdin-1097 2d.s2. 165741073us : __i915_request_submit: 0000:00:02.0 rcs0: fence 3:4660, current 4659 <0>[ 167.303044] drm_fdin-1097 2d.s1. 165741076us : execlists_submission_tasklet: 0000:00:02.0 rcs0: context:3 schedule-in, ccid:40 <0>[ 167.303095] drm_fdin-1097 2d.s1. 165741077us : trace_ports: 0000:00:02.0 rcs0: submit { ccid:40 3:4660* prio 2147483646 } <0>[ 167.303159] kworker/-89 11..... 165741139us : i915_request_retire.part.0: 0000:00:02.0 rcs0: fence c90:2, current 2 <0>[ 167.303208] kworker/-89 11..... 165741148us : __intel_context_do_unpin: 0000:00:02.0 rcs0: context:c90 unpin <0>[ 167.303272] kworker/-89 11..... 165741159us : i915_request_retire.part.0: 0000:00:02.0 rcs0: fence 1217:2, current 2 <0>[ 167.303321] kworker/-89 11..... 165741166us : __intel_context_do_unpin: 0000:00:02.0 rcs0: context:1217 unpin <0>[ 167.303384] kworker/-89 11..... 165741170us : i915_request_retire.part.0: 0000:00:02.0 rcs0: fence 3:4660, current 4660 <0>[ 167.303434] kworker/-89 11d..1. 165741172us : __intel_context_retire: 0000:00:02.0 rcs0: context:1216 retire runtime: { total:56028ns, avg:56028ns } <0>[ 167.303484] kworker/-89 11..... 165741198us : __engine_park: 0000:00:02.0 rcs0: parked <0>[ 167.303534] <idle>-0 5d.H3. 165741207us : execlists_irq_handler: 0000:00:02.0 rcs0: semaphore yield: 00000040 <0>[ 167.303583] kworker/-89 11..... 165741397us : __intel_context_retire: 0000:00:02.0 rcs0: context:1217 retire runtime: { total:325575ns, avg:0ns } <0>[ 167.303756] kworker/-89 11..... 165741777us : __intel_context_retire: 0000:00:02.0 rcs0: context:c90 retire runtime: { total:0ns, avg:0ns } <0>[ 167.303806] kworker/-89 11..... 165742017us : __engine_park: __engine_park:283 GEM_BUG_ON(engine->sched_engine->queue_priority_hint != (-((int)(~0U >> 1)) - 1)) <0>[ 167.303811] --------------------------------- <4>[ 167.304722] ------------[ cut here ]------------ <2>[ 167.304725] kernel BUG at drivers/gpu/drm/i915/gt/intel_engine_pm.c:283! <4>[ 167.304731] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI <4>[ 167.304734] CPU: 11 PID: 89 Comm: kworker/11:1 Tainted: G W 6.8.0-rc2-CI_DRM_14193-gc655e0fd2804+ #1 <4>[ 167.304736] Hardware name: Intel Corporation Rocket Lake Client Platform/RocketLake S UDIMM 6L RVP, BIOS RKLSFWI1.R00.3173.A03.2204210138 04/21/2022 <4>[ 167.304738] Workqueue: i915-unordered retire_work_handler [i915] <4>[ 16 ---truncated---

📍 영향받는 시스템

Linux kernel 6.8.0-rc2 이전 버전, Intel 통합 GPU (i915 드라이버) 탑재 시스템

⚔️ 공격 벡터

로컬 권한 필요, heartbeat 타이머를 통한 특정 GPU 작업 패턴 트리거로 커널 panic 유발

🛡️ 대응 방법

Linux 커널을 6.8.0-rc3 이상으로 업데이트 또는 queue_priority_hint 초기화 패치 적용

🔧 검증 코드

커널 버전의 주(Major).부(Minor) 번호 확인: 6.8 미만이면 취약할 수 있으며, dmesg에서 'GEM_BUG_ON' 또는 'queue_priority_hint' 관련 오류가 없는지 확인

Shell / Script
uname -r | grep -oE '^[0-9]+\.[0-9]+' | awk -F. '{if($1<6 || ($1==6 && $2<8)) print "6.8 미만"; else print "6.8 이상"}'

📊 CVSS Vector String

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

💻 영향받는 소프트웨어

Linux Kernel