{"id":"CVE-2026-64292","state":"PUBLISHED","title":"iommufd: Move vevent memory allocation outside spinlock","description":"In the Linux kernel, the following vulnerability has been resolved:\n\niommufd: Move vevent memory allocation outside spinlock\n\nThe veventq memory allocation happens inside the spinlock. Given its depth\nis decided by the user space, this leaves a vulnerability, where userspace\ncan allocate large queues to exhaust atomic memory reserves.\n\nMove the allocation outside the spinlock and use GFP_NOWAIT, which can fail\nfast under memory pressure without dipping into the GFP_ATOMIC reserves or\ndirect-reclaiming from the threaded IRQ handler. On allocation failure,\nqueue the lost_events_header (so userspace learns of the drop) and return\n-ENOMEM so the caller learns of the kernel-side memory pressure.\n\nThis is intentionally distinct from the queue-overflow path, which also\nqueues the lost_events_header but returns 0: a full queue is an expected\nuserspace-pacing condition rather than a kernel error.\n\nA subsequent change will cap the upper bound of the veventq_depth.","publishedAt":"2026-07-25T08:49:31.325Z","updatedAt":"2026-08-17T04:52:49.390Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e36ba5ab808ef6237c3148d469c8238674230e2b","status":"affected","lessThan":"779480ea79551c31964e74b9aef0e730faa3aa11","versionType":"git"},{"version":"e36ba5ab808ef6237c3148d469c8238674230e2b","status":"affected","lessThan":"6c5fc40200cd0a87d66a368eee00df4d1cca946e","versionType":"git"},{"version":"e36ba5ab808ef6237c3148d469c8238674230e2b","status":"affected","lessThan":"47443565d10c51366c9382dbc8597cd6c460b8a2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/iommufd/driver.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.15","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/iommufd/driver.c"]}],"references":["https://git.kernel.org/stable/c/779480ea79551c31964e74b9aef0e730faa3aa11","https://git.kernel.org/stable/c/6c5fc40200cd0a87d66a368eee00df4d1cca946e","https://git.kernel.org/stable/c/47443565d10c51366c9382dbc8597cd6c460b8a2"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64292.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64292","state":"PUBLISHED","datePublished":"2026-07-25T08:49:31.325Z","dateUpdated":"2026-08-17T04:52:49.390Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.778Z"},"containers":{"cna":{"title":"iommufd: Move vevent memory allocation outside spinlock","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\niommufd: Move vevent memory allocation outside spinlock\n\nThe veventq memory allocation happens inside the spinlock. Given its depth\nis decided by the user space, this leaves a vulnerability, where userspace\ncan allocate large queues to exhaust atomic memory reserves.\n\nMove the allocation outside the spinlock and use GFP_NOWAIT, which can fail\nfast under memory pressure without dipping into the GFP_ATOMIC reserves or\ndirect-reclaiming from the threaded IRQ handler. On allocation failure,\nqueue the lost_events_header (so userspace learns of the drop) and return\n-ENOMEM so the caller learns of the kernel-side memory pressure.\n\nThis is intentionally distinct from the queue-overflow path, which also\nqueues the lost_events_header but returns 0: a full queue is an expected\nuserspace-pacing condition rather than a kernel error.\n\nA subsequent change will cap the upper bound of the veventq_depth."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e36ba5ab808ef6237c3148d469c8238674230e2b","status":"affected","lessThan":"779480ea79551c31964e74b9aef0e730faa3aa11","versionType":"git"},{"version":"e36ba5ab808ef6237c3148d469c8238674230e2b","status":"affected","lessThan":"6c5fc40200cd0a87d66a368eee00df4d1cca946e","versionType":"git"},{"version":"e36ba5ab808ef6237c3148d469c8238674230e2b","status":"affected","lessThan":"47443565d10c51366c9382dbc8597cd6c460b8a2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/iommufd/driver.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.15","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/iommufd/driver.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/779480ea79551c31964e74b9aef0e730faa3aa11"},{"url":"https://git.kernel.org/stable/c/6c5fc40200cd0a87d66a368eee00df4d1cca946e"},{"url":"https://git.kernel.org/stable/c/47443565d10c51366c9382dbc8597cd6c460b8a2"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:52:49.390Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.1.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}