{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-47711", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-09-30T16:00:12.948Z", "datePublished": "2024-10-21T11:53:44.102Z", "dateUpdated": "2026-08-05T11:39:38.251Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:39:38.251Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\naf_unix: Don't return OOB skb in manage_oob().\n\nsyzbot reported use-after-free in unix_stream_recv_urg(). [0]\n\nThe scenario is\n\n 1. send(MSG_OOB)\n 2. recv(MSG_OOB)\n -> The consumed OOB remains in recv queue\n 3. send(MSG_OOB)\n 4. recv()\n -> manage_oob() returns the next skb of the consumed OOB\n -> This is also OOB, but unix_sk(sk)->oob_skb is not cleared\n 5. recv(MSG_OOB)\n -> unix_sk(sk)->oob_skb is used but already freed\n\nThe recent commit 8594d9b85c07 (\"af_unix: Don't call skb_get() for OOB\nskb.\") uncovered the issue.\n\nIf the OOB skb is consumed and the next skb is peeked in manage_oob(),\nwe still need to check if the skb is OOB.\n\nLet's do so by falling back to the following checks in manage_oob()\nand add the test case in selftest.\n\nNote that we need to add a similar check for SIOCATMARK.\n\n[0]:\nBUG: KASAN: slab-use-after-free in unix_stream_read_actor+0xa6/0xb0 net/unix/af_unix.c:2959\nRead of size 4 at addr ffff8880326abcc4 by task syz-executor178/5235\n\nCPU: 0 UID: 0 PID: 5235 Comm: syz-executor178 Not tainted 6.11.0-rc5-syzkaller-00742-gfbdaffe41adc #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024\nCall Trace:\n \n __dump_stack lib/dump_stack.c:93 [inline]\n dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119\n print_address_description mm/kasan/report.c:377 [inline]\n print_report+0x169/0x550 mm/kasan/report.c:488\n kasan_report+0x143/0x180 mm/kasan/report.c:601\n unix_stream_read_actor+0xa6/0xb0 net/unix/af_unix.c:2959\n unix_stream_recv_urg+0x1df/0x320 net/unix/af_unix.c:2640\n unix_stream_read_generic+0x2456/0x2520 net/unix/af_unix.c:2778\n unix_stream_recvmsg+0x22b/0x2c0 net/unix/af_unix.c:2996\n sock_recvmsg_nosec net/socket.c:1046 [inline]\n sock_recvmsg+0x22f/0x280 net/socket.c:1068\n ____sys_recvmsg+0x1db/0x470 net/socket.c:2816\n ___sys_recvmsg net/socket.c:2858 [inline]\n __sys_recvmsg+0x2f0/0x3e0 net/socket.c:2888\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7f5360d6b4e9\nCode: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007fff29b3a458 EFLAGS: 00000246 ORIG_RAX: 000000000000002f\nRAX: ffffffffffffffda RBX: 00007fff29b3a638 RCX: 00007f5360d6b4e9\nRDX: 0000000000002001 RSI: 0000000020000640 RDI: 0000000000000003\nRBP: 00007f5360dde610 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001\nR13: 00007fff29b3a628 R14: 0000000000000001 R15: 0000000000000001\n \n\nAllocated by task 5235:\n kasan_save_stack mm/kasan/common.c:47 [inline]\n kasan_save_track+0x3f/0x80 mm/kasan/common.c:68\n unpoison_slab_object mm/kasan/common.c:312 [inline]\n __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338\n kasan_slab_alloc include/linux/kasan.h:201 [inline]\n slab_post_alloc_hook mm/slub.c:3988 [inline]\n slab_alloc_node mm/slub.c:4037 [inline]\n kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4080\n __alloc_skb+0x1c3/0x440 net/core/skbuff.c:667\n alloc_skb include/linux/skbuff.h:1320 [inline]\n alloc_skb_with_frags+0xc3/0x770 net/core/skbuff.c:6528\n sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2815\n sock_alloc_send_skb include/net/sock.h:1778 [inline]\n queue_oob+0x108/0x680 net/unix/af_unix.c:2198\n unix_stream_sendmsg+0xd24/0xf80 net/unix/af_unix.c:2351\n sock_sendmsg_nosec net/socket.c:730 [inline]\n __sock_sendmsg+0x221/0x270 net/socket.c:745\n ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597\n ___sys_sendmsg net/socket.c:2651 [inline]\n __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2680\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nFreed by task 5235:\n kasan_save_stack mm/kasan/common.c:47\n---truncated---" } ], "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 - AF_UNIX is purely local IPC; the attacker must execute the send/recv syscall sequence on a local socketpair, with no network-reachable path to `manage_oob()`.\nAC:L - The five-step sequence is fully deterministic and driven entirely by the attacker within one process — no race, no timing window, and `CONFIG_AF_UNIX_OOB` is `default y` on effectively all kernels, so the vulnerable path is always compiled in.\nPR:L - Any unprivileged local user can call `socketpair(AF_UNIX, SOCK_STREAM)` and issue `MSG_OOB` sends/receives; no capability, root, or namespace setup is required.\nUI:N - A single attacker-controlled process performs both the send and receive sides of the sequence; no victim action or interaction is involved.\nS:U - The use-after-free corrupts kernel heap memory within the same kernel security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - `skb_copy_datagram_msg()` is invoked on the freed `skbuff_head_cache` object, copying data reached through its stale `data`/`len` fields to userspace; after heap grooming the reallocated object supplies an attacker-chosen pointer, giving arbitrary kernel memory read.\nI:H - The freed skb is written through `UNIXCB(oob_skb).consumed += 1` and its stale frag/frag_list pointers are walked, giving a heap-spray-able write into a general-purpose slab cache that is a well-known route to control-flow hijack.\nA:H - The syzbot report is a KASAN slab-use-after-free in `unix_stream_read_actor()`; the dangling dereference reliably oopses or panics the kernel and can be re-triggered at will by any local user." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/unix/af_unix.c", "tools/testing/selftests/net/af_unix/msg_oob.c" ], "versions": [ { "version": "93c99f21db360957d49853e5666b5c147f593bda", "lessThan": "4a7f9a2591a923bdde4bd7eac33490b6ae3b257c", "status": "affected", "versionType": "git" }, { "version": "93c99f21db360957d49853e5666b5c147f593bda", "lessThan": "5aa57d9f2d5311f19434d95b2a81610aa263e23b", "status": "affected", "versionType": "git" }, { "version": "71f8d9a4f6e094bae951765d1d18b44827013001", "status": "affected", "versionType": "git" }, { "version": "6.9.8", "lessThan": "6.10", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/unix/af_unix.c", "tools/testing/selftests/net/af_unix/msg_oob.c" ], "versions": [ { "version": "6.10", "status": "affected" }, { "version": "0", "lessThan": "6.10", "status": "unaffected", "versionType": "semver" }, { "version": "6.11.2", "lessThanOrEqual": "6.11.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12", "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": "6.10", "versionEndExcluding": "6.11.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "6.12" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9.8" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4a7f9a2591a923bdde4bd7eac33490b6ae3b257c" }, { "url": "https://git.kernel.org/stable/c/5aa57d9f2d5311f19434d95b2a81610aa263e23b" } ], "title": "af_unix: Don't return OOB skb in manage_oob().", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2024-47711", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-10-21T13:03:14.686039Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-10-21T13:04:18.955Z" } } ] } }