drm/i915: fix incorrect RCU teardown order
Summary
| CVE | CVE-2026-98521 |
|---|
| State | PUBLISHED |
|---|
| Assigner | Linux |
|---|
| Source Priority | CVE Program / NVD first with legacy fallback |
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| Published | 2026-10-18 16:17:03 UTC |
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| Updated | 2026-10-19 10:19:06 UTC |
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| Description | In the Linux kernel, the following vulnerability has been resolved:
drm/i915: fix incorrect RCU teardown order
i915_gem_busy_ioctl uses dma_resv_for_each_fence_unlocked() to iterate
over the fences in an GEM object without holding a reference but only
the RCU read side lock.
What can happen here is that the GEM object is destroyed concurrently
while i915_gem_busy_ioctl is still running. This won't free the GEM
objects memory, but still drops all the dma_fence references.
Now when dma_resv_for_each_fence_unlocked() sees a destroyed dma_fence it
assumes that a new fence list was installed and re-starts the loop.
But in the case of a destroyed GEM object a new fence list is never
installed, only the old one freed and therefore the iteration never
finishes resulting in an endless loop.
The solution is to drop the fence references only after the RCU grace
period.
The fixes tag is not necessary the patch introducing the problem, but the
one making it so worse that we need to address it.
This problem was pointed out by Sashiko-bot.
(cherry picked from commit 5113479556025093bf8133bb2dcaa33be2d50921) |
|---|
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected 912ff2ebd695c582ca4cebf833ad73a378a99f23 4d4ca84213327da1f84ef7af3946dea6b14c5d88 git |
Not specified |
| CNA |
Linux |
Linux |
affected 912ff2ebd695c582ca4cebf833ad73a378a99f23 c53db9cc245219af6b528ca022a17ebfa91d80ba git |
Not specified |
| CNA |
Linux |
Linux |
affected 912ff2ebd695c582ca4cebf833ad73a378a99f23 b12e041aedcf9fa77c6002a49f07eb20d0521b86 git |
Not specified |
| CNA |
Linux |
Linux |
affected 912ff2ebd695c582ca4cebf833ad73a378a99f23 cc890d3f1b15bf6481dc7270fba0b4fbba572813 git |
Not specified |
| CNA |
Linux |
Linux |
affected 912ff2ebd695c582ca4cebf833ad73a378a99f23 2dd0190e397ec6468095fd3e80e79276a7361449 git |
Not specified |
| CNA |
Linux |
Linux |
affected 912ff2ebd695c582ca4cebf833ad73a378a99f23 d2da6696e0c4e60414706e607029d0bb0330c67e git |
Not specified |
| CNA |
Linux |
Linux |
affected 5.17 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.17 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.1.189 6.1.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.6.158 6.6.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.12.112 6.12.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.18.55 6.18.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.2.9 7.2.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.3 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/b12e041aedcf9fa77c6002a49f07eb20d0521b86 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/c53db9cc245219af6b528ca022a17ebfa91d80ba |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/d2da6696e0c4e60414706e607029d0bb0330c67e |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/2dd0190e397ec6468095fd3e80e79276a7361449 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/4d4ca84213327da1f84ef7af3946dea6b14c5d88 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/cc890d3f1b15bf6481dc7270fba0b4fbba572813 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| CVE Program record |
CVE.ORG |
www.cve.org |
canonical |
| NVD vulnerability detail |
NVD |
nvd.nist.gov |
canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.