CVEvulnerability
CVE-2026-90426
- 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: Free the error IRQ before tearing down VINTFs
tegra241_cmdqv_remove() tears each VINTF down first, then calls free_irq().
Tearing a VINTF down frees vintf0 and clears cmdqv->vintfs[0]. An error in
that window makes tegra241_cmdqv_isr() read the stale slot and hand it to
tegra241_vintf0_handle_error(), which dereferences a NULL or freed pointer.
Free the IRQ before tearing the VINTFs down. free_irq() waits for in-flight
handlers to finish and blocks new ones, so no ISR can observe a VINTF as it
is torn down.
Note: a user-owned VINTF (viommu) could outlive this teardown, which unmaps
cmdqv->base and frees cmdqv->vintfs, so a later viommu close then touches
freed memory. This is neither introduced nor fixed here: a physical IOMMU
is not a pluggable device, so iommufd by design holds no reference on the
one behind a viommu, and this teardown is not expected while that viommu is
still alive.
References
- https://git.kernel.org/stable/c/076a4f5b1fc2016b973a12bc2ebb9b730e5e1e48 git.kernel.org
- https://git.kernel.org/stable/c/421f5ab135cd4a1353891e5bf2602cfc3c01afc7 git.kernel.org
- https://git.kernel.org/stable/c/61f0d437988e5730b04442f6a7d30a9907339f2a git.kernel.org
- https://git.kernel.org/stable/c/735698e81f798b4c02dcb6291ffbdd1b962c8c66 git.kernel.org