CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
AI Score
Confidence
Low
EPSS
Percentile
5.0%
In the Linux kernel, the following vulnerability has been resolved:
drm/i915/gt: Fix potential UAF by revoke of fence registers
CI has been sporadically reporting the following issue triggered by
igt@i915_selftest@live@hangcheck on ADL-P and similar machines:
<6> [414.049203] i915: Running intel_hangcheck_live_selftests/igt_reset_evict_fence
…
<6> [414.068804] i915 0000:00:02.0: [drm] GT0: GUC: submission enabled
<6> [414.068812] i915 0000:00:02.0: [drm] GT0: GUC: SLPC enabled
<3> [414.070354] Unable to pin Y-tiled fence; err:-4
<3> [414.071282] i915_vma_revoke_fence:301 GEM_BUG_ON(!i915_active_is_idle(&fence->active))
…
<4>[ 609.603992] ------------[ cut here ]------------
<2>[ 609.603995] kernel BUG at drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c:301!
<4>[ 609.604003] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
<4>[ 609.604006] CPU: 0 PID: 268 Comm: kworker/u64:3 Tainted: G U W 6.9.0-CI_DRM_14785-g1ba62f8cea9c+ #1
<4>[ 609.604008] Hardware name: Intel Corporation Alder Lake Client Platform/AlderLake-P DDR4 RVP, BIOS RPLPFWI1.R00.4035.A00.2301200723 01/20/2023
<4>[ 609.604010] Workqueue: i915 __i915_gem_free_work [i915]
<4>[ 609.604149] RIP: 0010:i915_vma_revoke_fence+0x187/0x1f0 [i915]
…
<4>[ 609.604271] Call Trace:
<4>[ 609.604273] <TASK>
…
<4>[ 609.604716] __i915_vma_evict+0x2e9/0x550 [i915]
<4>[ 609.604852] __i915_vma_unbind+0x7c/0x160 [i915]
<4>[ 609.604977] force_unbind+0x24/0xa0 [i915]
<4>[ 609.605098] i915_vma_destroy+0x2f/0xa0 [i915]
<4>[ 609.605210] __i915_gem_object_pages_fini+0x51/0x2f0 [i915]
<4>[ 609.605330] __i915_gem_free_objects.isra.0+0x6a/0xc0 [i915]
<4>[ 609.605440] process_scheduled_works+0x351/0x690
…
In the past, there were similar failures reported by CI from other IGT
tests, observed on other platforms.
Before commit 63baf4f3d587 (“drm/i915/gt: Only wait for GPU activity
before unbinding a GGTT fence”), i915_vma_revoke_fence() was waiting for
idleness of vma->active via fence_update(). That commit introduced
vma->fence->active in order for the fence_update() to be able to wait
selectively on that one instead of vma->active since only idleness of
fence registers was needed. But then, another commit 0d86ee35097a
(“drm/i915/gt: Make fence revocation unequivocal”) replaced the call to
fence_update() in i915_vma_revoke_fence() with only fence_write(), and
also added that GEM_BUG_ON(!i915_active_is_idle(&fence->active)) in front.
No justification was provided on why we might then expect idleness of
vma->fence->active without first waiting on it.
The issue can be potentially caused by a race among revocation of fence
registers on one side and sequential execution of signal callbacks invoked
on completion of a request that was using them on the other, still
processed in parallel to revocation of those fence registers. Fix it by
waiting for idleness of vma->fence->active in i915_vma_revoke_fence().
(cherry picked from commit 24bb052d3dd499c5956abad5f7d8e4fd07da7fb1)
Vendor | Product | Version | CPE |
---|---|---|---|
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
[
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c"
],
"versions": [
{
"version": "0d86ee35097a",
"lessThan": "f771b91f21c4",
"status": "affected",
"versionType": "git"
},
{
"version": "0d86ee35097a",
"lessThan": "29c0fdf49078",
"status": "affected",
"versionType": "git"
},
{
"version": "0d86ee35097a",
"lessThan": "ca0fabd365a2",
"status": "affected",
"versionType": "git"
},
{
"version": "0d86ee35097a",
"lessThan": "06dec31a0a51",
"status": "affected",
"versionType": "git"
},
{
"version": "0d86ee35097a",
"lessThan": "414f4a31f7a8",
"status": "affected",
"versionType": "git"
},
{
"version": "0d86ee35097a",
"lessThan": "996c3412a065",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c"
],
"versions": [
{
"version": "5.8",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.8",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.10.221",
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.15.162",
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.1.97",
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.6.37",
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.9.8",
"lessThanOrEqual": "6.9.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.10",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
]
git.kernel.org/stable/c/06dec31a0a5112a91f49085e8a8fa1a82296d5c7
git.kernel.org/stable/c/29c0fdf49078ab161570d3d1c6e13d66f182717d
git.kernel.org/stable/c/414f4a31f7a811008fd9a33b06216b060bad18fc
git.kernel.org/stable/c/996c3412a06578e9d779a16b9e79ace18125ab50
git.kernel.org/stable/c/ca0fabd365a27a94a36e68a7a02df8ff3c13dac6
git.kernel.org/stable/c/f771b91f21c46ad1217328d05e72a2c7e3add535