{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.1.5-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  sockmap: Fix use-after-free in udp_bpf_recvmsg()  syzbot reported use-after-free of struct sk_msg in sk_msg_recvmsg(). [0]  sk_msg_recvmsg() peeks sk_msg from psock-\u003eingress_msg under a lock, but its processing is lockless.  Thus, sk_msg_recvmsg() must be serialised by callers, otherwise multiple threads could touch the same sk_msg.  For example, TCP uses lock_sock(), and AF_UNIX uses unix_sk(sk)-\u003eiolock.  Initially, udp_bpf_recvmsg() had used lock_sock(), but the cited commit removed it.  Let's serialise sk_msg_recvmsg() with lock_sock() in udp_bpf_recvmsg().  Note that holding spin_lock_bh(\u0026sk-\u003esk_receive_queue.lock) is not an option due to copy_page_to_iter() in sk_msg_recvmsg().  [0]: BUG: KASAN: slab-use-after-free in sk_msg_recvmsg+0xb54/0xc30 net/core/skmsg.c:428 Read of size 4 at addr ffff88814cdcf000 by task syz.0.24/6020  CPU: 1 UID: 0 PID: 6020 Comm: syz.0.24 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 Call Trace:  \u003cTASK\u003e  dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120  print_address_description mm/kasan/report.c:378 [inline]  print_report+0xba/0x230 mm/kasan/report.c:482  kasan_report+0x117/0x150 mm/kasan/report.c:595  sk_msg_recvmsg+0xb54/0xc30 net/core/skmsg.c:428  udp_bpf_recvmsg+0x4bd/0xe00 net/ipv4/udp_bpf.c:84  inet_recvmsg+0x260/0x270 net/ipv4/af_inet.c:891  sock_recvmsg_nosec net/socket.c:1078 [inline]  sock_recvmsg+0x1a8/0x270 net/socket.c:1100  ____sys_recvmsg+0x1e6/0x4a0 net/socket.c:2812  ___sys_recvmsg+0x215/0x590 net/socket.c:2854  do_recvmmsg+0x334/0x800 net/socket.c:2949  __sys_recvmmsg net/socket.c:3023 [inline]  __do_sys_recvmmsg net/socket.c:3046 [inline]  __se_sys_recvmmsg net/socket.c:3039 [inline]  __x64_sys_recvmmsg+0x198/0x250 net/socket.c:3039  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]  do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94  entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb319f9aeb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 \u003c48\u003e 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb31ad97028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fb31a216090 RCX: 00007fb319f9aeb9 RDX: 0000000000000001 RSI: 0000200000000400 RDI: 0000000000000004 RBP: 00007fb31a008c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000040000021 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb31a216128 R14: 00007fb31a216090 R15: 00007ffe21dd0a98  \u003c/TASK\u003e  Allocated by task 6019:  kasan_save_stack mm/kasan/common.c:57 [inline]  kasan_save_track+0x3e/0x80 mm/kasan/common.c:78  poison_kmalloc_redzone mm/kasan/common.c:398 [inline]  __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415  kasan_kmalloc include/linux/kasan.h:263 [inline]  __kmalloc_cache_noprof+0x3d1/0x6e0 mm/slub.c:5780  kmalloc_noprof include/linux/slab.h:957 [inline]  kzalloc_noprof include/linux/slab.h:1094 [inline]  alloc_sk_msg net/core/skmsg.c:510 [inline]  sk_psock_skb_ingress_self+0x60/0x350 net/core/skmsg.c:612  sk_psock_verdict_apply net/core/skmsg.c:1038 [inline]  sk_psock_verdict_recv+0x7d9/0x8d0 net/core/skmsg.c:1236  udp_read_skb+0x73e/0x7e0 net/ipv4/udp.c:2045  sk_psock_verdict_data_ready+0x12d/0x550 net/core/skmsg.c:1257  __udp_enqueue_schedule_skb+0xc54/0x10b0 net/ipv4/udp.c:1789  __udp_queue_rcv_skb net/ipv4/udp.c:2346 [inline]  udp_queue_rcv_one_skb+0xac5/0x19c0 net/ipv4/udp.c:2475  __udp4_lib_mcast_deliver+0xc06/0xcf0 net/ipv4/udp.c:2585  __udp4_lib_rcv+0x10f6/0x2620 net/ipv4/udp.c:2724  ip_protocol_deliver_rcu+0x282/0x440 net/ipv4/ip_input.c:207  ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:241  NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318  dst_input include/net/dst.h:474 [inline]  ip_sublist_rcv_finish+0x221/0x2a0 net/ipv4/ip_input.c:584  ip_list_rcv_finish net/ipv4/ip_inp ---truncated---",
  "id": "DEBIAN-CVE-2026-74257",
  "modified": "2026-09-14T16:47:47.698858806Z",
  "published": "2026-08-15T06:22:24.870Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-74257"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-74257"
  ]
}