{
  "cveId": "CVE-2024-26732",
  "url": "https://patchblox.com/security/cve/CVE-2024-26732",
  "summary": "CVE-2024-26732 is fixed in linux on 1 platform, first by DEBIAN-CVE-2024-26732, released April 3, 2024. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  net: implement lockless setsockopt(SO_PEEK_OFF)...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  net: implement lockless setsockopt(SO_PEEK_OFF)  syzbot reported a lockdep violation [1] involving af_unix support of SO_PEEK_OFF.  Since SO_PEEK_OFF is inherently not thread safe (it uses a per-socket sk_peek_off field), there is really no point to enforce a pointless thread safety in the kernel.  After this patch :  - setsockopt(SO_PEEK_OFF) no longer acquires the socket lock.  - skb_consume_udp() no longer has to acquire the socket lock.  - af_unix no longer needs a special version of sk_set_peek_off(),   because it does not lock u-\u003Eiolock anymore.  As a followup, we could replace prot-\u003Eset_peek_off to be a boolean and avoid an indirect call, since we always use sk_set_peek_off().  [1]  WARNING: possible circular locking dependency detected 6.8.0-rc4-syzkaller-00267-g0f1dd5e91e2b #0 Not tainted  syz-executor.2/30025 is trying to acquire lock:  ffff8880765e7d80 (\u0026u-\u003Eiolock){\u002B.\u002B.}-{3:3}, at: unix_set_peek_off\u002B0x26/0xa0 net/unix/af_unix.c:789  but task is already holding lock:  ffff8880765e7930 (sk_lock-AF_UNIX){\u002B.\u002B.}-{0:0}, at: lock_sock include/net/sock.h:1691 [inline]  ffff8880765e7930 (sk_lock-AF_UNIX){\u002B.\u002B.}-{0:0}, at: sockopt_lock_sock net/core/sock.c:1060 [inline]  ffff8880765e7930 (sk_lock-AF_UNIX){\u002B.\u002B.}-{0:0}, at: sk_setsockopt\u002B0xe52/0x3360 net/core/sock.c:1193  which lock already depends on the new lock.  the existing dependency chain (in reverse order) is:  -\u003E #1 (sk_lock-AF_UNIX){\u002B.\u002B.}-{0:0}:         lock_acquire\u002B0x1e3/0x530 kernel/locking/lockdep.c:5754         lock_sock_nested\u002B0x48/0x100 net/core/sock.c:3524         lock_sock include/net/sock.h:1691 [inline]         __unix_dgram_recvmsg\u002B0x1275/0x12c0 net/unix/af_unix.c:2415         sock_recvmsg_nosec\u002B0x18e/0x1d0 net/socket.c:1046         ____sys_recvmsg\u002B0x3c0/0x470 net/socket.c:2801         ___sys_recvmsg net/socket.c:2845 [inline]         do_recvmmsg\u002B0x474/0xae0 net/socket.c:2939         __sys_recvmmsg net/socket.c:3018 [inline]         __do_sys_recvmmsg net/socket.c:3041 [inline]         __se_sys_recvmmsg net/socket.c:3034 [inline]         __x64_sys_recvmmsg\u002B0x199/0x250 net/socket.c:3034        do_syscall_64\u002B0xf9/0x240        entry_SYSCALL_64_after_hwframe\u002B0x6f/0x77  -\u003E #0 (\u0026u-\u003Eiolock){\u002B.\u002B.}-{3:3}:         check_prev_add kernel/locking/lockdep.c:3134 [inline]         check_prevs_add kernel/locking/lockdep.c:3253 [inline]         validate_chain\u002B0x18ca/0x58e0 kernel/locking/lockdep.c:3869         __lock_acquire\u002B0x1345/0x1fd0 kernel/locking/lockdep.c:5137         lock_acquire\u002B0x1e3/0x530 kernel/locking/lockdep.c:5754         __mutex_lock_common kernel/locking/mutex.c:608 [inline]         __mutex_lock\u002B0x136/0xd70 kernel/locking/mutex.c:752         unix_set_peek_off\u002B0x26/0xa0 net/unix/af_unix.c:789        sk_setsockopt\u002B0x207e/0x3360         do_sock_setsockopt\u002B0x2fb/0x720 net/socket.c:2307         __sys_setsockopt\u002B0x1ad/0x250 net/socket.c:2334         __do_sys_setsockopt net/socket.c:2343 [inline]         __se_sys_setsockopt net/socket.c:2340 [inline]         __x64_sys_setsockopt\u002B0xb5/0xd0 net/socket.c:2340        do_syscall_64\u002B0xf9/0x240        entry_SYSCALL_64_after_hwframe\u002B0x6f/0x77  other info that might help us debug this:   Possible unsafe locking scenario:         CPU0                    CPU1        ----                    ----   lock(sk_lock-AF_UNIX);                                lock(\u0026u-\u003Eiolock);                                lock(sk_lock-AF_UNIX);   lock(\u0026u-\u003Eiolock);   *** DEADLOCK ***  1 lock held by syz-executor.2/30025:   #0: ffff8880765e7930 (sk_lock-AF_UNIX){\u002B.\u002B.}-{0:0}, at: lock_sock include/net/sock.h:1691 [inline]   #0: ffff8880765e7930 (sk_lock-AF_UNIX){\u002B.\u002B.}-{0:0}, at: sockopt_lock_sock net/core/sock.c:1060 [inline]   #0: ffff8880765e7930 (sk_lock-AF_UNIX){\u002B.\u002B.}-{0:0}, at: sk_setsockopt\u002B0xe52/0x3360 net/core/sock.c:1193  stack backtrace: CPU: 0 PID: 30025 Comm: syz-executor.2 Not tainted 6.8.0-rc4-syzkaller-00267-g0f1dd5e91e2b #0 Hardware name: Google Google C ---truncated---",
  "published": "2024-04-03T17:15:50Z",
  "severity": "medium",
  "cvss": 5.5,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00158,
  "epssPercentile": 0.0494,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.7.7-1",
      "fix": "DEBIAN-CVE-2024-26732",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2024-26732",
      "released": "2024-04-03T17:15:50Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "6.7.7-1",
      "fix": "DEBIAN-CVE-2024-26732",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2024-26732",
      "released": "2024-04-03T17:15:50Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T13:06:02Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}