iommu/tegra241-cmdqv: Free the error IRQ before tearing down VINTFs

Summary

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.

Timeline

1. Sep 17, 2026, 4:09 PM UTCCVE published
2. Oct 19, 2026, 9:03 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 918eb5c856f6ce4cf93b4b38e4b5e156905c5943 · fixed in 076a4f5b1fc2016b973a12bc2ebb9b730e5e1e48; From 918eb5c856f6ce4cf93b4b38e4b5e156905c5943 · fixed in 735698e81f798b4c02dcb6291ffbdd1b962c8c66; From 918eb5c856f6ce4cf93b4b38e4b5e156905c5943 · fixed in 421f5ab135cd4a1353891e5bf2602cfc3c01afc7; From 918eb5c856f6ce4cf93b4b38e4b5e156905c5943 · fixed in 61f0d437988e5730b04442f6a7d30a9907339f2a

• Linux Linux

  6.12

• KernelLinux

  From 6.12.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.52; From 6.19.0 · fixed in 7.2.6

References 4