In the Linux kernel, the following vulnerability has been resolved:
drm/xe/userptr: fix EFAULT handling
Currently we treat EFAULT from hmm_range_fault() as a non-fatal error
when called from xe_vm_userptr_pin() with the idea that we want to avoid
killing the entire vm and chucking an error, under the assumption that
the user just did an unmap or something, and has no intention of
actually touching that memory from the GPU. At this point we have
already zapped the PTEs so any access should generate a page fault, and
if the pin fails there also it will then become fatal.
However it looks like it's possible for the userptr vma to still be on
the rebind list in preempt_rebind_work_func(), if we had to retry the
pin again due to something happening in the caller before we did the
rebind step, but in the meantime needing to re-validate the userptr and
this time hitting the EFAULT.
This explains an internal user report of hitting:
[ 191.738349] WARNING: CPU: 1 PID: 157 at drivers/gpu/drm/xe/xe_res_cursor.h:158 xe_pt_stage_bind.constprop.0+0x60a/0x6b0 [xe]
[ 191.738551] Workqueue: xe-ordered-wq preempt_rebind_work_func [xe]
[ 191.738616] RIP: 0010:xe_pt_stage_bind.constprop.0+0x60a/0x6b0 [xe]
[ 191.738690] Call Trace:
[ 191.738692]
[ 191.738694] ? show_regs+0x69/0x80
[ 191.738698] ? __warn+0x93/0x1a0
[ 191.738703] ? xe_pt_stage_bind.constprop.0+0x60a/0x6b0 [xe]
[ 191.738759] ? report_bug+0x18f/0x1a0
[ 191.738764] ? handle_bug+0x63/0xa0
[ 191.738767] ? exc_invalid_op+0x19/0x70
[ 191.738770] ? asm_exc_invalid_op+0x1b/0x20
[ 191.738777] ? xe_pt_stage_bind.constprop.0+0x60a/0x6b0 [xe]
[ 191.738834] ? ret_from_fork_asm+0x1a/0x30
[ 191.738849] bind_op_prepare+0x105/0x7b0 [xe]
[ 191.738906] ? dma_resv_reserve_fences+0x301/0x380
[ 191.738912] xe_pt_update_ops_prepare+0x28c/0x4b0 [xe]
[ 191.738966] ? kmemleak_alloc+0x4b/0x80
[ 191.738973] ops_execute+0x188/0x9d0 [xe]
[ 191.739036] xe_vm_rebind+0x4ce/0x5a0 [xe]
[ 191.739098] ? trace_hardirqs_on+0x4d/0x60
[ 191.739112] preempt_rebind_work_func+0x76f/0xd00 [xe]
Followed by NPD, when running some workload, since the sg was never
actually populated but the vma is still marked for rebind when it should
be skipped for this special EFAULT case. This is confirmed to fix the
user report.
v2 (MattB):
v3 (MattB):
- Update the commit message to make it clear that this indeed fixes the
issue.
(cherry picked from commit 6b93cb98910c826c2e2004942f8b060311e43618)
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-05). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it