CVE-2026-74573

Summary

In the Linux kernel, the following vulnerability has been resolved:

iommu/arm-smmu-v3-iommufd: Require exactly one Stream ID for a vDEVICE

arm_vsmmu_vsid_to_sid() maps a guest's vSID to a single physical Stream ID taken from master->streams[0], assuming a device has exactly one stream. A device with several streams gets only its first one mapped, so a guest vSID invalidation cannot reach the others' ATC and IOTLB entries; a device with none makes master->streams a ZERO_SIZE_PTR, read out of bounds.

Add an arm_vsmmu_vdevice_init() op to reject the vDEVICE with -EOPNOTSUPP when master->num_streams is not one, rather than mapping it silently.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxd68beb276ba26cec47350a6d468e967673ee0c56 < 3808bab5d95ae79e333e11f6a73d178e084c645daffected
LinuxLinuxd68beb276ba26cec47350a6d468e967673ee0c56 < 0acbc621341aca4eb94d9c2f43e1ab273ff088f0affected
LinuxLinuxd68beb276ba26cec47350a6d468e967673ee0c56 < c3b8ee84a965058b41275069d4696f37a8b14bf6affected
LinuxLinux6.13affected
LinuxLinux0 < 6.13unaffected
LinuxLinux6.18.44 <= 6.18.*unaffected
LinuxLinux7.1.8 <= 7.1.*unaffected
LinuxLinux7.2-rc6 <= *unaffected

Weaknesses

References