{"id":"CVE-2024-35880","state":"PUBLISHED","title":"io_uring/kbuf: hold io_buffer_list reference over mmap","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/kbuf: hold io_buffer_list reference over mmap\n\nIf we look up the kbuf, ensure that it doesn't get unregistered until\nafter we're done with it. Since we're inside mmap, we cannot safely use\nthe io_uring lock. Rely on the fact that we can lookup the buffer list\nunder RCU now and grab a reference to it, preventing it from being\nunregistered until we're done with it. The lookup returns the\nio_buffer_list directly with it referenced.","publishedAt":"2024-05-19T08:34:37.262Z","updatedAt":"2026-08-05T11:30:38.073Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/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":"09f7520048eaaee9709091cd2787966f807da7c5","status":"affected","lessThan":"65938e81df2197203bda4b9a0c477e7987218d66","versionType":"git"},{"version":"5cf4f52e6d8aa2d3b7728f568abbf9d42a3af252","status":"affected","lessThan":"5fd8e2359498043e0b5329a05f02d10a9eb91eb9","versionType":"git"},{"version":"5cf4f52e6d8aa2d3b7728f568abbf9d42a3af252","status":"affected","lessThan":"561e4f9451d65fc2f7eef564e0064373e3019793","versionType":"git"},{"version":"6.6.5","status":"affected","lessThan":"6.6.26","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["io_uring/io_uring.c","io_uring/kbuf.c","io_uring/kbuf.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.7","versionType":"semver"},{"version":"6.6.26","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.8.5","status":"unaffected","lessThanOrEqual":"6.8.*","versionType":"semver"},{"version":"6.9","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["io_uring/io_uring.c","io_uring/kbuf.c","io_uring/kbuf.h"]}],"references":["https://git.kernel.org/stable/c/65938e81df2197203bda4b9a0c477e7987218d66","https://git.kernel.org/stable/c/5fd8e2359498043e0b5329a05f02d10a9eb91eb9","https://git.kernel.org/stable/c/561e4f9451d65fc2f7eef564e0064373e3019793"],"weaknesses":[],"ingestedAt":"2026-10-29T20:07:30.303Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/35xxx/CVE-2024-35880.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-35880","state":"PUBLISHED","datePublished":"2024-05-19T08:34:37.262Z","dateUpdated":"2026-08-05T11:30:38.073Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-05-17T13:50:33.111Z"},"containers":{"cna":{"title":"io_uring/kbuf: hold io_buffer_list reference over mmap","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/kbuf: hold io_buffer_list reference over mmap\n\nIf we look up the kbuf, ensure that it doesn't get unregistered until\nafter we're done with it. Since we're inside mmap, we cannot safely use\nthe io_uring lock. Rely on the fact that we can lookup the buffer list\nunder RCU now and grab a reference to it, preventing it from being\nunregistered until we're done with it. The lookup returns the\nio_buffer_list directly with it referenced."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"09f7520048eaaee9709091cd2787966f807da7c5","status":"affected","lessThan":"65938e81df2197203bda4b9a0c477e7987218d66","versionType":"git"},{"version":"5cf4f52e6d8aa2d3b7728f568abbf9d42a3af252","status":"affected","lessThan":"5fd8e2359498043e0b5329a05f02d10a9eb91eb9","versionType":"git"},{"version":"5cf4f52e6d8aa2d3b7728f568abbf9d42a3af252","status":"affected","lessThan":"561e4f9451d65fc2f7eef564e0064373e3019793","versionType":"git"},{"version":"6.6.5","status":"affected","lessThan":"6.6.26","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["io_uring/io_uring.c","io_uring/kbuf.c","io_uring/kbuf.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.7","versionType":"semver"},{"version":"6.6.26","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.8.5","status":"unaffected","lessThanOrEqual":"6.8.*","versionType":"semver"},{"version":"6.9","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["io_uring/io_uring.c","io_uring/kbuf.c","io_uring/kbuf.h"]}],"references":[{"url":"https://git.kernel.org/stable/c/65938e81df2197203bda4b9a0c477e7987218d66"},{"url":"https://git.kernel.org/stable/c/5fd8e2359498043e0b5329a05f02d10a9eb91eb9"},{"url":"https://git.kernel.org/stable/c/561e4f9451d65fc2f7eef564e0064373e3019793"}],"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 vulnerable path is entered only through local syscalls on an io_uring file descriptor — `mmap()` with `IORING_OFF_PBUF_RING` racing `io_uring_register(IORING_UNREGISTER_PBUF_RING)`. There is no network, adjacent, or remote-peer path into `io_uring_validate_mmap_request()`.\nAC:L - The attacker owns both sides of the race: one thread loops `mmap()` on the provided-buffer-ring offset while a second thread loops register/unregister of the same bgid on the same fd, with unlimited retries and no dependence on any condition outside the attacker's control.\nPR:L - Only an unprivileged local account is required — `io_uring_allowed()` permits any user when `sysctl_io_uring_disabled` is 0, which is the kernel default, and `IORING_REGISTER_PBUF_RING` with `IOU_PBUF_RING_MMAP` carries no capability check. This is reachable from inside containers and sandboxes as well.\nUI:N - The attacker performs every step itself — creating the ring, registering the buffer ring, and driving both racing threads. No victim action or interaction with any other user is needed.\nS:U - The defect and its consequences are confined to kernel memory within the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - Without the reference, mmap consumes a `bl->buf_ring` address belonging to a buffer list being concurrently destroyed, and `remap_pfn_range()` installs a persistent `VM_PFNMAP` window onto kernel-allocated ring memory that has already been released back to the context's reusable region pool and can be re-handed to a different buffer group — an uncontrolled read of kernel memory, and per use-after-free scoring this is High.\nI:H - The resulting mapping is a writable `MAP_SHARED` view of that stale kernel region, so the attacker can write into memory the kernel no longer treats as belonging to the mapping's owner; use-after-free of a refcounted object also enables heap grooming toward a controlled-write primitive.\nA:H - Racing the teardown lets mmap operate on a `buf_ring` pointer being NULLed and on an `io_buffer_list` on its way to `kfree_rcu()`, producing oops/kernel panic; the race is repeatable at will by any local user, so availability loss is complete."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T11:30:38.073Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.5","versionEndExcluding":"6.6.26"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.8.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.9"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","affected":[{"vendor":"linux","product":"linux_kernel","defaultStatus":"affected","versions":[{"version":"6.7","status":"affected"}],"cpes":["cpe:2.3:o:linux:linux_kernel:6.7:-:*:*:*:*:*:*"]},{"vendor":"linux","product":"linux_kernel","defaultStatus":"affected","versions":[{"version":"09f7520048ea","status":"affected","lessThan":"65938e81df21","versionType":"git"},{"version":"5cf4f52e6d8a","status":"affected","lessThan":"5fd8e2359498","versionType":"git"},{"version":"5cf4f52e6d8a","status":"affected","lessThan":"561e4f9451d6","versionType":"git"}],"cpes":["cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2024-08-01T03:55:54.843818Z","id":"CVE-2024-35880","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-08-01T13:23:38.879Z"}},{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/65938e81df2197203bda4b9a0c477e7987218d66","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/5fd8e2359498043e0b5329a05f02d10a9eb91eb9","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/561e4f9451d65fc2f7eef564e0064373e3019793","tags":["x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-02T03:21:48.591Z"}}]}}}