{"id":"CVE-2026-90427","state":"PUBLISHED","title":"iommu/tegra241-cmdqv: Don't fall back to a freed smmu after devm_krealloc()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\niommu/tegra241-cmdqv: Don't fall back to a freed smmu after devm_krealloc()\n\n__tegra241_cmdqv_probe() uses devm_krealloc() to grow @smmu into the larger\ntegra241_cmdqv, which frees the original @smmu once it relocates. A failure\nafter that returned NULL, and the caller then dereferenced the freed @smmu\non its fallback path.\n\nReturn an int and take @smmu by reference instead, then update *smmu to the\nreallocated pointer after devm_krealloc() succeeds, so the caller and its\nfallback path both use the live @smmu rather than the freed original.","publishedAt":"2026-09-17T16:09:49.121Z","updatedAt":"2026-10-21T12:51:38.034Z","severity":{"score":7.4,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"918eb5c856f6ce4cf93b4b38e4b5e156905c5943","status":"affected","lessThan":"ea2edb27ef2648d8687cd0fc3ec3ba1793436e7e","versionType":"git"},{"version":"918eb5c856f6ce4cf93b4b38e4b5e156905c5943","status":"affected","lessThan":"268cbe3a36ae57a2ec09601f343b92f6f092d505","versionType":"git"},{"version":"918eb5c856f6ce4cf93b4b38e4b5e156905c5943","status":"affected","lessThan":"86197679b293f0601c3331d545f99a70a7780aa9","versionType":"git"},{"version":"918eb5c856f6ce4cf93b4b38e4b5e156905c5943","status":"affected","lessThan":"d4d05f55e9da646ec03adfa77260eb46f4163749","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.12","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c"]}],"references":["https://git.kernel.org/stable/c/ea2edb27ef2648d8687cd0fc3ec3ba1793436e7e","https://git.kernel.org/stable/c/268cbe3a36ae57a2ec09601f343b92f6f092d505","https://git.kernel.org/stable/c/86197679b293f0601c3331d545f99a70a7780aa9","https://git.kernel.org/stable/c/d4d05f55e9da646ec03adfa77260eb46f4163749"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/90xxx/CVE-2026-90427.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-90427","state":"PUBLISHED","datePublished":"2026-09-17T16:09:49.121Z","dateUpdated":"2026-10-21T12:51:38.034Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.814Z"},"containers":{"cna":{"title":"iommu/tegra241-cmdqv: Don't fall back to a freed smmu after devm_krealloc()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\niommu/tegra241-cmdqv: Don't fall back to a freed smmu after devm_krealloc()\n\n__tegra241_cmdqv_probe() uses devm_krealloc() to grow @smmu into the larger\ntegra241_cmdqv, which frees the original @smmu once it relocates. A failure\nafter that returned NULL, and the caller then dereferenced the freed @smmu\non its fallback path.\n\nReturn an int and take @smmu by reference instead, then update *smmu to the\nreallocated pointer after devm_krealloc() succeeds, so the caller and its\nfallback path both use the live @smmu rather than the freed original."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"918eb5c856f6ce4cf93b4b38e4b5e156905c5943","status":"affected","lessThan":"ea2edb27ef2648d8687cd0fc3ec3ba1793436e7e","versionType":"git"},{"version":"918eb5c856f6ce4cf93b4b38e4b5e156905c5943","status":"affected","lessThan":"268cbe3a36ae57a2ec09601f343b92f6f092d505","versionType":"git"},{"version":"918eb5c856f6ce4cf93b4b38e4b5e156905c5943","status":"affected","lessThan":"86197679b293f0601c3331d545f99a70a7780aa9","versionType":"git"},{"version":"918eb5c856f6ce4cf93b4b38e4b5e156905c5943","status":"affected","lessThan":"d4d05f55e9da646ec03adfa77260eb46f4163749","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.12","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/ea2edb27ef2648d8687cd0fc3ec3ba1793436e7e"},{"url":"https://git.kernel.org/stable/c/268cbe3a36ae57a2ec09601f343b92f6f092d505"},{"url":"https://git.kernel.org/stable/c/86197679b293f0601c3331d545f99a70a7780aa9"},{"url":"https://git.kernel.org/stable/c/d4d05f55e9da646ec03adfa77260eb46f4163749"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":7.4,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The UAF is reached from arm_smmu_device_probe() → arm_smmu_impl_probe() → tegra241_cmdqv_probe() → __tegra241_cmdqv_probe() when ACPI IORT (acpi_iort_init()/iort_add_platform_device(\"arm-smmu-v3\")) or DT nvidia,tegra264-smmu binds the SMMU. No protocol message supplies the stale pointer; it is a local devm_krealloc() lifetime bug.\nAC:H - out_fallback uses the freed @smmu only if a relocating devm_krealloc() is followed by kzalloc_objs(cmdqv->vintfs) or request_threaded_irq() failing. arm_smmu_driver sets suppress_bind_attrs, CONFIG_ARM_SMMU_V3=y, and this probe never returns -EPROBE_DEFER, so a local attacker cannot re-enter it or reliably force those GFP_KERNEL/IRQ failures.\nPR:N - arm_smmu_device_probe() has no capable() check; tegra241_cmdqv_probe() runs from the platform .probe in kernel_init once IORT creates the arm-smmu-v3 device or DT matches nvidia,tegra264-smmu. No OS account or user-namespace capability is required to be on that path.\nUI:N - tegra241_cmdqv_probe()’s out_fallback dereference of the freed @smmu runs inside arm_smmu_device_probe() during automatic platform bind; no victim must mount a filesystem, open a device node, or load a module by hand.\nS:U - The use-after-free is of the host kernel arm_smmu_device that devm_krealloc() freed in __tegra241_cmdqv_probe(); out_fallback’s smmu->options write and the rest of arm_smmu_device_probe() stay in that kernel. This is not leftover SMMU translation tables or a guest/DMA walk of attacker-controlled IOMMU page tables.\nC:H - After a relocating devm_krealloc(), tegra241_cmdqv_probe() returns ERR_PTR(-ENODEV) and arm_smmu_impl_probe() hands the freed @smmu back to arm_smmu_device_probe(). That use-after-free of the SMMU object can be reclaimed and, per kernel UAF guidance, enables arbitrary kernel memory disclosure.\nI:H - out_fallback writes smmu->options through the freed pointer, then arm_smmu_device_probe() continues with arm_smmu_device_hw_probe(), arm_smmu_init_structures(), and iommu_device_register() on the same dangling arm_smmu_device, a write-after-free that yields heap-spray write and control-flow hijack primitives.\nA:H - out_fallback dereferences smmu->impl_dev and later SMMU probe/runtime uses the freed arm_smmu_device; that use-after-free oopses or panics the kernel even when not turned into a full exploit."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-21T12:51:38.034Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12","versionEndExcluding":"6.18.57"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12","versionEndExcluding":"7.2.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}