Description
In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Avoid NULL pointer dereference or refcount corruption Commit 60f030f7418d ("iommu/vt-d: Avoid use of NULL after WARN_ON_ONCE") fixed a NULL pointer dereference in an unlikely situation partly. If dev_pasid is not found in the dev_pasids list, it remains NULL. However, the teardown operations are executed unconditionally, this lead to a NULL pointer dereference or refcount corruption. If the domain was never attached to this IOMMU, info will be NULL, which would cause an immediate dereference when checking --info->refcnt. Even if info is not NULL, decrementing the refcount without having removed a valid PASID might unbalance the count. This could lead to premature dropping of the refcount to 0, potentially causing a use-after-free for the remaining active devices sharing the domain. Fix it by returning early if dev_pasid is NULL, before executing the teardown operations. Issue found by AI review and suggested by Kevin Tian. https://sashiko.dev/#/patchset/20260421031347.1408890-1-zhenzhong.duan%40intel.com
CVSS breakdown
Affected products
- Linux / Linux60f030f7418d3f1d94f2fb207fe3080e1844630b – 9022cb9ac0c2a72a57fa8ebf92ac74f953ca0153
- Linux / Linux60f030f7418d3f1d94f2fb207fe3080e1844630b – cdfe3c9f2c9e28a8651ee463c88ad191ced2f840
- Linux / Linux60f030f7418d3f1d94f2fb207fe3080e1844630b – 79ea2feb917b05366b49d85573c9c5331f043b2c
- Linux / Linux68ec78beb4a3fb0877cbaaf49758c85410c05977 – 68ec78beb4a3fb0877cbaaf49758c85410c05977
- Linux / Linuxdf96876be3b064aefc493f760e0639765d13ed0d – df96876be3b064aefc493f760e0639765d13ed0d
- Linux / Linux6.12.57 – 6.13
- Linux / Linux6.13.3 – 6.14
- Linux / Linux6.14 – 6.14
- Linux / Linux0 – 6.14
- Linux / Linux6.18.33 – 6.18.*
- Linux / Linux7.0.10 – 7.0.*
- Linux / Linux7.1 – *