CVE-2026-43368: drm/i915: Fix potential overflow of shmem scatterlist length
In the Linux kernel, the following vulnerability has been resolved:
drm/i915: Fix potential overflow of shmem scatterlist length
When a scatterlists table of a GEM shmem object of size 4 GB or more is populated with pages allocated from a folio, unsigned int .length attribute of a scatterlist may get overflowed if total byte length of pages allocated to that single scatterlist happens to reach or cross the 4GB limit. As a consequence, users of the object may suffer from hitting unexpected, premature end of the object's backing pages.
[278.780187] ------------[ cut here ]------------ [278.780377] WARNING: CPU: 1 PID: 2326 at drivers/gpu/drm/i915/i915mm.c:55 remapsg+0x199/0x1d0 [i915] ... [278.780654] CPU: 1 UID: 0 PID: 2326 Comm: gemmmapoffset Tainted: G S U 6.17.0-rc1-CIDRM16981-ged823aaa0607+ #1 PREEMPT(voluntary) [278.780656] Tainted: [S]=CPUOUTOFSPEC, [U]=USER [278.780658] Hardware name: Intel Corporation Meteor Lake Client Platform/MTL-P LP5x T3 RVP, BIOS MTLPFWI1.R00.3471.D91.2401310918 01/31/2024 [278.780659] RIP: 0010:remapsg+0x199/0x1d0 [i915] ... [278.780786] Call Trace: [278.780787] <TASK> [278.780788] ? applytopagerange+0x3e6/0x910 [278.780795] ? pfxremapsg+0x10/0x10 [i915] [278.780906] applytopagerange+0x14/0x30 [278.780908] remapiosg+0x14d/0x260 [i915] [278.781013] vmfaultcpu+0xd2/0x330 [i915] [278.781137] dofault+0x3a/0x1b0 [278.781140] dofault+0x322/0x640 [278.781143] handlemmfault+0x938/0xfd0 [278.781150] handlemmfault+0x12c/0x300 [278.781152] ? lockmmandfindvma+0x4b/0x760 [278.781155] douseraddrfault+0x2d6/0x8e0 [278.781160] excpagefault+0x96/0x2c0 [278.781165] asmexcpagefault+0x27/0x30 ...
That issue was apprehended by the author of a change that introduced it, and potential risk even annotated with a comment, but then never addressed.
When adding folio pages to a scatterlist table, take care of byte length of any single scatterlist not exceeding maxsegment.
(cherry picked from commit 06249b4e691a75694c014a61708c007fb5755f60)
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Linux kernel (drivers/gpu/drm/i915)to a version that resolves this vulnerability.Fixed in 6.17.0-rc1-CI_DRM_16981-ged823aaa0607+
Event History
Frequently Asked Questions
What is the severity of CVE-2026-43368?
CVE-2026-43368 has a medium severity level due to potential overflow issues in shmem scatterlist length.
How do I fix CVE-2026-43368?
To fix CVE-2026-43368, ensure your Linux kernel is updated to the latest version that includes this fix for the drm/i915 component.
Which software is affected by CVE-2026-43368?
CVE-2026-43368 affects the Intel drm/i915 component within the Linux kernel.
What types of systems are at risk for CVE-2026-43368?
Systems using Intel graphics with the affected drm/i915 kernel component are at risk for CVE-2026-43368.
Is CVE-2026-43368 related to memory management issues?
Yes, CVE-2026-43368 involves potential overflow issues associated with memory management of scatterlists in the drm/i915 implementation.