In the Linux kernel, the following vulnerability has been resolved:
iommu/tegra241-cmdqv: Fix warnings due to dmam_free_coherent()
Two WARNINGs are observed when SMMU driver rolls back upon failure:
arm-smmu-v3.9.auto: Failed to register iommu
arm-smmu-v3.9.auto: probe with driver arm-smmu-v3 failed with error -22
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WARNING: CPU: 5 PID: 1 at kernel/dma/mapping.c:74 dmam_free_coherent+0xc0/0xd8
Call trace:
dmam_free_coherent+0xc0/0xd8 (P)
tegra241_vintf_free_lvcmdq+0x74/0x188
tegra241_cmdqv_remove_vintf+0x60/0x148
tegra241_cmdqv_remove+0x48/0xc8
arm_smmu_impl_remove+0x28/0x60
devm_action_release+0x1c/0x40
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WARNING: CPU: 16 PID: 1 at mm/page_alloc.c:6902 free_contig_range+0x18c/0x1c8
Call trace:
free_contig_range+0x18c/0x1c8 (P)
cma_release+0x154/0x2f0
dma_free_contiguous+0x38/0xa0
dma_direct_free+0x10c/0x248
dma_free_attrs+0x100/0x290
dmam_free_coherent+0x78/0xd8
tegra241_vintf_free_lvcmdq+0x74/0x160
tegra241_cmdqv_remove+0x98/0x198
arm_smmu_impl_remove+0x28/0x60
devm_action_release+0x1c/0x40
This is because the LVCMDQ queue memory are managed by devres, while that
dmam_free_coherent() is called in the context of devm_action_release().
Jason pointed out that "arm_smmu_impl_probe() has mis-ordered the devres
callbacks if ops->device_remove() is going to be manually freeing things
that probe allocated":
https://lore.kernel.org/linux-iommu/[email protected]/
In fact, tegra241_cmdqv_init_structures() only allocates memory resources
which means any failure that it generates would be similar to -ENOMEM, so
there is no point in having that "falling back to standard SMMU" routine,
as the standard SMMU would likely fail to allocate memory too.
Remove the unwind part in tegra241_cmdqv_init_structures(), and return a
proper error code to ask SMMU driver to call tegra241_cmdqv_remove() via
impl_ops->device_remove(). Then, drop tegra241_vintf_free_lvcmdq() since
devres will take care of that.
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
- 0.3% 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