{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-40954","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-07-12T12:17:45.592Z","datePublished":"2024-07-12T12:31:57.517Z","dateUpdated":"2026-08-05T11:34:13.912Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T11:34:13.912Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: do not leave a dangling sk pointer, when socket creation fails\n\nIt is possible to trigger a use-after-free by:\n  * attaching an fentry probe to __sock_release() and the probe calling the\n    bpf_get_socket_cookie() helper\n  * running traceroute -I 1.1.1.1 on a freshly booted VM\n\nA KASAN enabled kernel will log something like below (decoded and stripped):\n==================================================================\nBUG: KASAN: slab-use-after-free in __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)\nRead of size 8 at addr ffff888007110dd8 by task traceroute/299\n\nCPU: 2 PID: 299 Comm: traceroute Tainted: G            E      6.10.0-rc2+ #2\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014\nCall Trace:\n <TASK>\ndump_stack_lvl (lib/dump_stack.c:117 (discriminator 1))\nprint_report (mm/kasan/report.c:378 mm/kasan/report.c:488)\n? __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)\nkasan_report (mm/kasan/report.c:603)\n? __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)\nkasan_check_range (mm/kasan/generic.c:183 mm/kasan/generic.c:189)\n__sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)\nbpf_get_socket_ptr_cookie (./arch/x86/include/asm/preempt.h:94 ./include/linux/sock_diag.h:42 net/core/filter.c:5094 net/core/filter.c:5092)\nbpf_prog_875642cf11f1d139___sock_release+0x6e/0x8e\nbpf_trampoline_6442506592+0x47/0xaf\n__sock_release (net/socket.c:652)\n__sock_create (net/socket.c:1601)\n...\nAllocated by task 299 on cpu 2 at 78.328492s:\nkasan_save_stack (mm/kasan/common.c:48)\nkasan_save_track (mm/kasan/common.c:68)\n__kasan_slab_alloc (mm/kasan/common.c:312 mm/kasan/common.c:338)\nkmem_cache_alloc_noprof (mm/slub.c:3941 mm/slub.c:4000 mm/slub.c:4007)\nsk_prot_alloc (net/core/sock.c:2075)\nsk_alloc (net/core/sock.c:2134)\ninet_create (net/ipv4/af_inet.c:327 net/ipv4/af_inet.c:252)\n__sock_create (net/socket.c:1572)\n__sys_socket (net/socket.c:1660 net/socket.c:1644 net/socket.c:1706)\n__x64_sys_socket (net/socket.c:1718)\ndo_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)\nentry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)\n\nFreed by task 299 on cpu 2 at 78.328502s:\nkasan_save_stack (mm/kasan/common.c:48)\nkasan_save_track (mm/kasan/common.c:68)\nkasan_save_free_info (mm/kasan/generic.c:582)\npoison_slab_object (mm/kasan/common.c:242)\n__kasan_slab_free (mm/kasan/common.c:256)\nkmem_cache_free (mm/slub.c:4437 mm/slub.c:4511)\n__sk_destruct (net/core/sock.c:2117 net/core/sock.c:2208)\ninet_create (net/ipv4/af_inet.c:397 net/ipv4/af_inet.c:252)\n__sock_create (net/socket.c:1572)\n__sys_socket (net/socket.c:1660 net/socket.c:1644 net/socket.c:1706)\n__x64_sys_socket (net/socket.c:1718)\ndo_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)\nentry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)\n\nFix this by clearing the struct socket reference in sk_common_release() to cover\nall protocol families create functions, which may already attached the\nreference to the sk object with sock_init_data()."}],"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 dangling pointer is created by the local `socket(2)` syscall reaching `__sock_create()` → `inet_create()` and failing after `sock_init_data()`; no packet or remote peer data is involved in reaching the vulnerable code. The dereference likewise happens in the syscalling task's own context.\nAC:L - `ping_init_sock()` returns -EACCES for every user under the kernel-default empty `ping_group_range` ([1,0]), so `socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP)` frees `sk` and leaves `sock->sk` dangling deterministically on every attempt, with no race to win and no memory layout outside the attacker's influence. On a target running the socket-lifecycle eBPF instrumentation that constitutes the vulnerable configuration, the freed-object access follows unconditionally.\nPR:L - Any ordinary unprivileged local account — including an unprivileged container tenant — can issue the failing `socket()` call; there is no capability check, no user-namespace requirement, and even `traceroute` run by a normal user triggers it. The privileges needed to install the tracing probe belong to the host's monitoring stack, not to the attacker.\nUI:N - The attacker performs the entire sequence with a single syscall from their own process; no other user must open a file, mount anything, or take any action.\nS:U - The freed `struct sock` and the corrupting access are both inside the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - This is a slab use-after-free read of the freed `struct sock` (`atomic64_read(&sk->sk_cookie)` at a controllable offset into a reallocated object), and the value read is returned to the reader — a UAF read of kernel heap contents that can disclose whatever has been sprayed into the reclaimed slot.\nI:H - `__sock_gen_cookie()` does not merely read: with `sk_cookie == 0` it performs an `atomic64_cmpxchg()`, writing 8 bytes into the freed object, so a reallocated victim structure occupying that slot is corrupted at a fixed offset. A use-after-free write into sprayed heap memory is a real corruption primitive with control-flow-hijack potential.\nA:H - The use-after-free reliably produces KASAN slab-use-after-free reports and, on a production kernel, corrupts arbitrary reclaimed slab objects, causing oopses and panics; the trigger can be repeated in a tight loop by an unprivileged user."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/sock.c"],"versions":[{"version":"c5dbb89fc2ac013afe67b9e4fcb3743c02b567cd","lessThan":"78e4aa528a7b1204219d808310524344f627d069","status":"affected","versionType":"git"},{"version":"c5dbb89fc2ac013afe67b9e4fcb3743c02b567cd","lessThan":"893eeba94c40d513cd0fe6539330ebdaea208c0e","status":"affected","versionType":"git"},{"version":"c5dbb89fc2ac013afe67b9e4fcb3743c02b567cd","lessThan":"454c454ed645fed051216b79622f7cb69c1638f5","status":"affected","versionType":"git"},{"version":"c5dbb89fc2ac013afe67b9e4fcb3743c02b567cd","lessThan":"5dfe2408fd7dc4d2e7ac38a116ff0a37b1cfd3b9","status":"affected","versionType":"git"},{"version":"c5dbb89fc2ac013afe67b9e4fcb3743c02b567cd","lessThan":"6cd4a78d962bebbaf8beb7d2ead3f34120e3f7b2","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/sock.c"],"versions":[{"version":"5.12","status":"affected"},{"version":"0","lessThan":"5.12","status":"unaffected","versionType":"semver"},{"version":"5.15.162","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.96","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.36","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.9.7","lessThanOrEqual":"6.9.*","status":"unaffected","versionType":"semver"},{"version":"6.10","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":"5.12","versionEndExcluding":"5.15.162"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.1.96"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.6.36"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.9.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.10"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/78e4aa528a7b1204219d808310524344f627d069"},{"url":"https://git.kernel.org/stable/c/893eeba94c40d513cd0fe6539330ebdaea208c0e"},{"url":"https://git.kernel.org/stable/c/454c454ed645fed051216b79622f7cb69c1638f5"},{"url":"https://git.kernel.org/stable/c/5dfe2408fd7dc4d2e7ac38a116ff0a37b1cfd3b9"},{"url":"https://git.kernel.org/stable/c/6cd4a78d962bebbaf8beb7d2ead3f34120e3f7b2"}],"title":"net: do not leave a dangling sk pointer, when socket creation fails","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/78e4aa528a7b1204219d808310524344f627d069","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/893eeba94c40d513cd0fe6539330ebdaea208c0e","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/454c454ed645fed051216b79622f7cb69c1638f5","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/5dfe2408fd7dc4d2e7ac38a116ff0a37b1cfd3b9","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/6cd4a78d962bebbaf8beb7d2ead3f34120e3f7b2","tags":["x_transferred"]},{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"}],"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2025-11-03T21:58:18.562Z"}},{"metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2024-40954","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-09-10T17:03:48.944366Z"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2024-09-11T17:34:24.382Z"}}]}}