2025-02-03 17:04:00 +00:00

128 lines
11 KiB
JSON

{
"id": "CVE-2024-26732",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2024-04-03T17:15:50.977",
"lastModified": "2025-02-03T16:17:25.537",
"vulnStatus": "Analyzed",
"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->iolock anymore.\n\nAs a followup, we could replace prot->set_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 (&u->iolock){+.+.}-{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-> #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-> #0 (&u->iolock){+.+.}-{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(&u->iolock);\n lock(sk_lock-AF_UNIX);\n lock(&u->iolock);\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->iolock. Como seguimiento, podr\u00edamos reemplazar prot->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 (&u->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: -> #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 -> #0 (&u->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(&u->iolock); bloquear(sk_lock-AF_UNIX); bloquear(&u->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---"
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "nvd@nist.gov",
"type": "Primary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.8,
"impactScore": 3.6
}
]
},
"weaknesses": [
{
"source": "nvd@nist.gov",
"type": "Primary",
"description": [
{
"lang": "en",
"value": "CWE-667"
}
]
}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.7",
"versionEndExcluding": "6.7.7",
"matchCriteriaId": "575EE16B-67F2-4B5B-B5F8-1877715C898B"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:6.8:rc1:*:*:*:*:*:*",
"matchCriteriaId": "B9F4EA73-0894-400F-A490-3A397AB7A517"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:6.8:rc2:*:*:*:*:*:*",
"matchCriteriaId": "056BD938-0A27-4569-B391-30578B309EE3"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:6.8:rc3:*:*:*:*:*:*",
"matchCriteriaId": "F02056A5-B362-4370-9FF8-6F0BD384D520"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:6.8:rc4:*:*:*:*:*:*",
"matchCriteriaId": "62075ACE-B2A0-4B16-829D-B3DA5AE5CC41"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:6.8:rc5:*:*:*:*:*:*",
"matchCriteriaId": "A780F817-2A77-4130-A9B7-5C25606314E3"
}
]
}
]
}
],
"references": [
{
"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": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"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",
"source": "af854a3a-2127-422b-91ae-364da2661108",
"tags": [
"Patch"
]
}
]
}