CVEvulnerability
CVE-2026-90430
- Status
- Received
- Published
- 2026-09-17
- Last modified
- 2026-10-19
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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.
References
- https://git.kernel.org/stable/c/792f720fc23fe5bd6508d40ed73ae739debd6dcb git.kernel.org
- https://git.kernel.org/stable/c/b4535b403d6bf9bcc24dbd62096711329b9c612c git.kernel.org
- https://git.kernel.org/stable/c/cbc41aacd49e695338940196e7084770365e1b68 git.kernel.org
- https://git.kernel.org/stable/c/d5ec248ee1c79354979c23f7f390e856e9535651 git.kernel.org