In the Linux kernel, the following vulnerability has been resolved:
iommu/tegra241-cmdqv: Publish an LVCMDQ only after it is fully initialized
tegra241_vintf_init_lvcmdq() stores the freshly allocated vcmdq pointer to
the vintf->lvcmdqs[] array, before tegra241_vcmdq_alloc_smmu_cmdq() builds
the vcmdq->cmdq. The error ISR dereferences that cmdq, so a latched LVCMDQ
error (e.g. one inherited across a kexec) firing in this window would make
tegra241_vintf0_handle_error() pass the still-zeroed arm_smmu_cmdq down to
__arm_smmu_cmdq_skip_err(), dereferencing NULL queue register pointers.
Drop the store from tegra241_vintf_init_lvcmdq() and publish the vcmdq at
the end of the allocation instead, with an smp_store_release() that pairs
with an smp_load_acquire() in the ISR, which can see a fully built LVCMDQ
or NULL.
The user-owned LVCMDQ allocation moves accordingly, publishing the vcmdq
once tegra241_vcmdq_hw_init_user() succeeds, using a plain store since a
user VINTF's lvcmdqs[] has no lockless reader -- the error ISR only walks
the VINTF0 array.
iommu/tegra241-cmdqv: Publish an LVCMDQ only after it is fully initialized
tegra241_vintf_init_lvcmdq() stores the freshly allocated vcmdq pointer to
the vintf->lvcmdqs[] array, before tegra241_vcmdq_alloc_smmu_cmdq() builds
the vcmdq->cmdq. The error ISR dereferences that cmdq, so a latched LVCMDQ
error (e.g. one inherited across a kexec) firing in this window would make
tegra241_vintf0_handle_error() pass the still-zeroed arm_smmu_cmdq down to
__arm_smmu_cmdq_skip_err(), dereferencing NULL queue register pointers.
Drop the store from tegra241_vintf_init_lvcmdq() and publish the vcmdq at
the end of the allocation instead, with an smp_store_release() that pairs
with an smp_load_acquire() in the ISR, which can see a fully built LVCMDQ
or NULL.
The user-owned LVCMDQ allocation moves accordingly, publishing the vcmdq
once tegra241_vcmdq_hw_init_user() succeeds, using a plain store since a
user VINTF's lvcmdqs[] has no lockless reader -- the error ISR only walks
the VINTF0 array.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 17 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: iommu/tegra241-cmdqv: Publish an LVCMDQ only after it is fully initialized tegra241_vintf_init_lvcmdq() stores the freshly allocated vcmdq pointer to the vintf->lvcmdqs[] array, before tegra241_vcmdq_alloc_smmu_cmdq() builds the vcmdq->cmdq. The error ISR dereferences that cmdq, so a latched LVCMDQ error (e.g. one inherited across a kexec) firing in this window would make tegra241_vintf0_handle_error() pass the still-zeroed arm_smmu_cmdq down to __arm_smmu_cmdq_skip_err(), dereferencing NULL queue register pointers. Drop the store from tegra241_vintf_init_lvcmdq() and publish the vcmdq at the end of the allocation instead, with an smp_store_release() that pairs with an smp_load_acquire() in the ISR, which can see a fully built LVCMDQ or NULL. The user-owned LVCMDQ allocation moves accordingly, publishing the vcmdq once tegra241_vcmdq_hw_init_user() succeeds, using a plain store since a user VINTF's lvcmdqs[] has no lockless reader -- the error ISR only walks the VINTF0 array. | |
| Title | iommu/tegra241-cmdqv: Publish an LVCMDQ only after it is fully initialized | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-17T16:09:51.101Z
Reserved: 2026-09-11T19:38:34.815Z
Link: CVE-2026-90430
No data.
Status : Received
Published: 2026-09-17T17:17:47.997
Modified: 2026-09-17T17:17:47.997
Link: CVE-2026-90430
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.