fkie_cve-2024-26732
Vulnerability from fkie_nvd
Published
2024-04-03 17:15
Modified
2025-02-03 16:17
Severity ?
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
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->iolock anymore. As a followup, we could replace prot->set_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 (&u->iolock){+.+.}-{3:3}, at: unix_set_peek_off+0x26/0xa0 net/unix/af_unix.c:789 but task is already holding lock: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1691 [inline] ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sockopt_lock_sock net/core/sock.c:1060 [inline] ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sk_setsockopt+0xe52/0x3360 net/core/sock.c:1193 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (sk_lock-AF_UNIX){+.+.}-{0:0}: lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 lock_sock_nested+0x48/0x100 net/core/sock.c:3524 lock_sock include/net/sock.h:1691 [inline] __unix_dgram_recvmsg+0x1275/0x12c0 net/unix/af_unix.c:2415 sock_recvmsg_nosec+0x18e/0x1d0 net/socket.c:1046 ____sys_recvmsg+0x3c0/0x470 net/socket.c:2801 ___sys_recvmsg net/socket.c:2845 [inline] do_recvmmsg+0x474/0xae0 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+0x199/0x250 net/socket.c:3034 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 -> #0 (&u->iolock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 unix_set_peek_off+0x26/0xa0 net/unix/af_unix.c:789 sk_setsockopt+0x207e/0x3360 do_sock_setsockopt+0x2fb/0x720 net/socket.c:2307 __sys_setsockopt+0x1ad/0x250 net/socket.c:2334 __do_sys_setsockopt net/socket.c:2343 [inline] __se_sys_setsockopt net/socket.c:2340 [inline] __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sk_lock-AF_UNIX); lock(&u->iolock); lock(sk_lock-AF_UNIX); lock(&u->iolock); *** DEADLOCK *** 1 lock held by syz-executor.2/30025: #0: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1691 [inline] #0: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sockopt_lock_sock net/core/sock.c:1060 [inline] #0: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sk_setsockopt+0xe52/0x3360 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---
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/56667da7399eb19af857e30f41bea89aa6fa812cPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/897f75e2cde8a5f9f7529b55249af1fa4248c83bPatch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/56667da7399eb19af857e30f41bea89aa6fa812cPatch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/897f75e2cde8a5f9f7529b55249af1fa4248c83bPatch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel 6.8
linux linux_kernel 6.8
linux linux_kernel 6.8
linux linux_kernel 6.8
linux linux_kernel 6.8


To clipboard 

{
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          "cpeMatch": [
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              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "575EE16B-67F2-4B5B-B5F8-1877715C898B",
              "versionEndExcluding": "6.7.7",
              "versionStartIncluding": "6.7",
              "vulnerable": true
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  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: implement lockless setsockopt(SO_PEEK_OFF)\n\nsyzbot reported a lockdep violation [1] involving af_unix\nsupport of SO_PEEK_OFF.\n\nSince SO_PEEK_OFF is inherently not thread safe (it uses a per-socket\nsk_peek_off field), there is really no point to enforce a pointless\nthread safety in the kernel.\n\nAfter this patch :\n\n- setsockopt(SO_PEEK_OFF) no longer acquires the socket lock.\n\n- skb_consume_udp() no longer has to acquire the socket lock.\n\n- af_unix no longer needs a special version of sk_set_peek_off(),\n  because it does not lock u-\u003eiolock anymore.\n\nAs a followup, we could replace prot-\u003eset_peek_off to be a boolean\nand avoid an indirect call, since we always use sk_set_peek_off().\n\n[1]\n\nWARNING: possible circular locking dependency detected\n6.8.0-rc4-syzkaller-00267-g0f1dd5e91e2b #0 Not tainted\n\nsyz-executor.2/30025 is trying to acquire lock:\n ffff8880765e7d80 (\u0026u-\u003eiolock){+.+.}-{3:3}, at: unix_set_peek_off+0x26/0xa0 net/unix/af_unix.c:789\n\nbut task is already holding lock:\n ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1691 [inline]\n ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sockopt_lock_sock net/core/sock.c:1060 [inline]\n ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sk_setsockopt+0xe52/0x3360 net/core/sock.c:1193\n\nwhich lock already depends on the new lock.\n\nthe existing dependency chain (in reverse order) is:\n\n-\u003e #1 (sk_lock-AF_UNIX){+.+.}-{0:0}:\n        lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754\n        lock_sock_nested+0x48/0x100 net/core/sock.c:3524\n        lock_sock include/net/sock.h:1691 [inline]\n        __unix_dgram_recvmsg+0x1275/0x12c0 net/unix/af_unix.c:2415\n        sock_recvmsg_nosec+0x18e/0x1d0 net/socket.c:1046\n        ____sys_recvmsg+0x3c0/0x470 net/socket.c:2801\n        ___sys_recvmsg net/socket.c:2845 [inline]\n        do_recvmmsg+0x474/0xae0 net/socket.c:2939\n        __sys_recvmmsg net/socket.c:3018 [inline]\n        __do_sys_recvmmsg net/socket.c:3041 [inline]\n        __se_sys_recvmmsg net/socket.c:3034 [inline]\n        __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3034\n       do_syscall_64+0xf9/0x240\n       entry_SYSCALL_64_after_hwframe+0x6f/0x77\n\n-\u003e #0 (\u0026u-\u003eiolock){+.+.}-{3:3}:\n        check_prev_add kernel/locking/lockdep.c:3134 [inline]\n        check_prevs_add kernel/locking/lockdep.c:3253 [inline]\n        validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869\n        __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137\n        lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754\n        __mutex_lock_common kernel/locking/mutex.c:608 [inline]\n        __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752\n        unix_set_peek_off+0x26/0xa0 net/unix/af_unix.c:789\n       sk_setsockopt+0x207e/0x3360\n        do_sock_setsockopt+0x2fb/0x720 net/socket.c:2307\n        __sys_setsockopt+0x1ad/0x250 net/socket.c:2334\n        __do_sys_setsockopt net/socket.c:2343 [inline]\n        __se_sys_setsockopt net/socket.c:2340 [inline]\n        __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340\n       do_syscall_64+0xf9/0x240\n       entry_SYSCALL_64_after_hwframe+0x6f/0x77\n\nother info that might help us debug this:\n\n Possible unsafe locking scenario:\n\n       CPU0                    CPU1\n       ----                    ----\n  lock(sk_lock-AF_UNIX);\n                               lock(\u0026u-\u003eiolock);\n                               lock(sk_lock-AF_UNIX);\n  lock(\u0026u-\u003eiolock);\n\n *** DEADLOCK ***\n\n1 lock held by syz-executor.2/30025:\n  #0: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1691 [inline]\n  #0: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sockopt_lock_sock net/core/sock.c:1060 [inline]\n  #0: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sk_setsockopt+0xe52/0x3360 net/core/sock.c:1193\n\nstack backtrace:\nCPU: 0 PID: 30025 Comm: syz-executor.2 Not tainted 6.8.0-rc4-syzkaller-00267-g0f1dd5e91e2b #0\nHardware name: Google Google C\n---truncated---"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: net: implementar lockless setsockopt(SO_PEEK_OFF) syzbot inform\u00f3 una violaci\u00f3n de lockdep [1] que involucraba el soporte de SO_PEEK_OFF por parte de af_unix. Dado que SO_PEEK_OFF no es inherentemente seguro para subprocesos (utiliza un campo sk_peek_off por socket), realmente no tiene sentido imponer una seguridad de subprocesos in\u00fatil en el kernel. Despu\u00e9s de este parche: - setsockopt(SO_PEEK_OFF) ya no adquiere el bloqueo del socket. - skb_consume_udp() ya no tiene que adquirir el bloqueo del socket. - af_unix ya no necesita una versi\u00f3n especial de sk_set_peek_off(), porque ya no bloquea u-\u0026gt;iolock. Como seguimiento, podr\u00edamos reemplazar prot-\u0026gt;set_peek_off para que sea booleano y evitar una llamada indirecta, ya que siempre usamos sk_set_peek_off(). [1] ADVERTENCIA: posible dependencia de bloqueo circular detectada 6.8.0-rc4-syzkaller-00267-g0f1dd5e91e2b #0 No contaminado syz-executor.2/30025 est\u00e1 intentando adquirir el bloqueo: ffff8880765e7d80 (\u0026amp;u-\u0026gt;iolock){+.+. }-{3:3}, en: unix_set_peek_off+0x26/0xa0 net/unix/af_unix.c:789 pero la tarea ya mantiene el bloqueo: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, en: lock_sock include/net/sock.h:1691 [en l\u00ednea] ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, en: sockopt_lock_sock net/core/sock.c:1060 [en l\u00ednea] ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, en: sk_setsockopt+0xe52/0x3360 net/core/sock.c:1193 cuyo bloqueo ya depende del nuevo bloqueo. la cadena de dependencia existente (en orden inverso) es: -\u0026gt; #1 (sk_lock-AF_UNIX){+.+.}-{0:0}: lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 lock_sock_nested+0x48 /0x100 net/core/sock.c:3524 lock_sock include/net/sock.h:1691 [en l\u00ednea] __unix_dgram_recvmsg+0x1275/0x12c0 net/unix/af_unix.c:2415 sock_recvmsg_nosec+0x18e/0x1d0 net/socket.c:1046 ____sys_recvmsg+0x3c0/0x470 net/socket.c:2801 ___sys_recvmsg net/socket.c:2845 [en l\u00ednea] do_recvmmsg+0x474/0xae0 net/socket.c:2939 __sys_recvmmsg net/socket.c:3018 [en l\u00ednea] __do_sy s_recvmmsg red/socket .c:3041 [en l\u00ednea] __se_sys_recvmmsg net/socket.c:3034 [en l\u00ednea] __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3034 do_syscall_64+0xf9/0x240 Entry_SYSCALL_64_after_hwframe+0x6f/0x77 -\u0026gt; #0 (\u0026amp;u-\u0026gt;iolock) {+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [en l\u00ednea] check_prevs_add kernel/locking/lockdep.c:3253 [en l\u00ednea] validar_chain+0x18ca/0x58e0 kernel/locking/lockdep. c:3869 __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:608 [en l\u00ednea] __mutex_lock+0x136/0xd70 kernel /locking/mutex.c:752 unix_set_peek_off+0x26/0xa0 net/unix/af_unix.c:789 sk_setsockopt+0x207e/0x3360 do_sock_setsockopt+0x2fb/0x720 net/socket.c:2307 __sys_setsockopt+0x1ad/0x250 net/ enchufe.c: 2334 __do_sys_setsockopt net/socket.c:2343 [en l\u00ednea] __se_sys_setsockopt net/socket.c:2340 [en l\u00ednea] __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340 do_syscall_64+0xf9/0x240 entrada_SYSCALL_6 4_after_hwframe+0x6f/0x77 otra informaci\u00f3n que podr\u00eda ayudar depuremos esto: Posible escenario de bloqueo inseguro: CPU0 CPU1 ---- ---- lock(sk_lock-AF_UNIX); bloquear(\u0026amp;u-\u0026gt;iolock); bloquear(sk_lock-AF_UNIX); bloquear(\u0026amp;u-\u0026gt;iolock); *** DEADLOCK *** 1 bloqueo retenido por syz-executor.2/30025: #0: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, en: lock_sock include/net/sock. h:1691 [en l\u00ednea] #0: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, en: sockopt_lock_sock net/core/sock.c:1060 [en l\u00ednea] #0: ffff8880765e7930 (sk_lock- AF_UNIX){+.+.}-{0:0}, en: sk_setsockopt+0xe52/0x3360 net/core/sock.c:1193 seguimiento de pila: CPU: 0 PID: 30025 Comm: syz-executor.2 No contaminado 6.8 .0-rc4-syzkaller-00267-g0f1dd5e91e2b #0 Nombre del hardware: Google Google C ---truncado---"
    }
  ],
  "id": "CVE-2024-26732",
  "lastModified": "2025-02-03T16:17:25.537",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2024-04-03T17:15:50.977",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/56667da7399eb19af857e30f41bea89aa6fa812c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/897f75e2cde8a5f9f7529b55249af1fa4248c83b"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/56667da7399eb19af857e30f41bea89aa6fa812c"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/897f75e2cde8a5f9f7529b55249af1fa4248c83b"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-667"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


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