{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74334","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-15T05:44:03.885Z","datePublished":"2026-08-15T05:58:26.455Z","dateUpdated":"2026-08-17T05:46:03.176Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-17T05:46:03.176Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/nldev: Fix locking when accessing mr->pd\n\nSashiko points out that, due to rereg_mr, the PD is actually variable and\nall the touches in nldev are racy.\n\nUse mr->device instead of mr->pd->device.\n\nGetting the PD restrack ID is more tricky. To avoid disturbing all the\nhappy paths, add an rdma_restrack_sync() operation which is sort of like\nflush_workqueue() or synchronize_irq(): after it returns, all the old\nnldev touches to the mr are gone and everything sees the new PD. This\nmakes it safe to reach into the PD pointer."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached via local NETLINK_RDMA nldev MR resource dumps and concurrent IB_USER_VERBS_CMD_REREG_MR ioctl on /dev/infiniband/uverbs; it is not triggered by remote RDMA/InfiniBand/RoCE network traffic.\nAC:L - An attacker controls both race sides by spawning threads that hammer rereg_mr with IB_MR_REREG_PD and nldev RES_MR_GET dumps, optionally deallocating the old PD; no timing or layout conditions outside attacker control are required.\nPR:L - Exploitation needs only local uverbs access (device nodes default 0666) plus NETLINK_RDMA dumps; CAP_NET_ADMIN for netlink send is obtainable by unprivileged users via user namespaces, not real init-namespace root.\nUI:N - No victim interaction is required; the attacker triggers both the rereg_mr PD change and the concurrent nldev MR dump from their own process.\nS:U - Impact is kernel heap corruption and privilege escalation within the host kernel security boundary, not a VM escape, IOMMU bypass, or cross-authority sandbox breakout.\nC:H - Concurrent rereg_mr can free the old ib_pd while nldev still dereferences mr->pd for device and res.id, creating a use-after-free that enables arbitrary kernel memory disclosure via controlled reuse of freed slab objects.\nI:H - The ib_pd UAF is exploitable for heap grooming and arbitrary kernel write or control-flow hijack, not merely a bounded data corruption or guaranteed crash.\nA:H - The race reliably causes kernel oops or panic from dereferencing a freed ib_pd during nldev dumps, and UAF exploitation can additionally crash or hang the system during heap manipulation."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/core/nldev.c","drivers/infiniband/core/restrack.c","drivers/infiniband/core/restrack.h","drivers/infiniband/core/uverbs_cmd.c","include/rdma/ib_verbs.h"],"versions":[{"version":"da5c8507821573b8ed6e3f47e009f273493ffaf7","lessThan":"1a132ee4e655288d9a0937ea5109a0d038431ae9","status":"affected","versionType":"git"},{"version":"da5c8507821573b8ed6e3f47e009f273493ffaf7","lessThan":"50d5c02ab8e62325548bd3a6e6b758a9dcd6e7c3","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/core/nldev.c","drivers/infiniband/core/restrack.c","drivers/infiniband/core/restrack.h","drivers/infiniband/core/uverbs_cmd.c","include/rdma/ib_verbs.h"],"versions":[{"version":"4.18","status":"affected"},{"version":"0","lessThan":"4.18","status":"unaffected","versionType":"semver"},{"version":"7.1.5","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.18","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.18","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/1a132ee4e655288d9a0937ea5109a0d038431ae9"},{"url":"https://git.kernel.org/stable/c/50d5c02ab8e62325548bd3a6e6b758a9dcd6e7c3"}],"title":"RDMA/nldev: Fix locking when accessing mr->pd","x_generator":{"engine":"bippy-1.2.0"}}}}