CVE-2021-47572

{"id": "CVE-2021-47572", "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "published": "2024-05-24T15:15:22.887", "references": [{"url": "https://git.kernel.org/stable/c/1c743127cc54b112b155f434756bd4b5fa565a99", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/39509d76a9a3d02f379d52cb4b1449469c56c0e0", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/7b6f44856da5ba0b1aa61403eb9fddd272156503", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b70ff391deeec35cdd8a05f5f63f5fe28bc4f225", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-476"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: nexthop: fix null pointer dereference when IPv6 is not enabled\n\nWhen we try to add an IPv6 nexthop and IPv6 is not enabled\n(!CONFIG_IPV6) we'll hit a NULL pointer dereference[1] in the error path\nof nh_create_ipv6() due to calling ipv6_stub->fib6_nh_release. The bug\nhas been present since the beginning of IPv6 nexthop gateway support.\nCommit 1aefd3de7bc6 (\"ipv6: Add fib6_nh_init and release to stubs\") tells\nus that only fib6_nh_init has a dummy stub because fib6_nh_release should\nnot be called if fib6_nh_init returns an error, but the commit below added\na call to ipv6_stub->fib6_nh_release in its error path. To fix it return\nthe dummy stub's -EAFNOSUPPORT error directly without calling\nipv6_stub->fib6_nh_release in nh_create_ipv6()'s error path.\n\n[1]\n Output is a bit truncated, but it clearly shows the error.\n BUG: kernel NULL pointer dereference, address: 000000000000000000\n #PF: supervisor instruction fetch in kernel modede\n #PF: error_code(0x0010) - not-present pagege\n PGD 0 P4D 0\n Oops: 0010 [#1] PREEMPT SMP NOPTI\n CPU: 4 PID: 638 Comm: ip Kdump: loaded Not tainted 5.16.0-rc1+ #446\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/01/2014\n RIP: 0010:0x0\n Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.\n RSP: 0018:ffff888109f5b8f0 EFLAGS: 00010286^Ac\n RAX: 0000000000000000 RBX: ffff888109f5ba28 RCX: 0000000000000000\n RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8881008a2860\n RBP: ffff888109f5b9d8 R08: 0000000000000000 R09: 0000000000000000\n R10: ffff888109f5b978 R11: ffff888109f5b948 R12: 00000000ffffff9f\n R13: ffff8881008a2a80 R14: ffff8881008a2860 R15: ffff8881008a2840\n FS: 00007f98de70f100(0000) GS:ffff88822bf00000(0000) knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: ffffffffffffffd6 CR3: 0000000100efc000 CR4: 00000000000006e0\n Call Trace:\n <TASK>\n nh_create_ipv6+0xed/0x10c\n rtm_new_nexthop+0x6d7/0x13f3\n ? check_preemption_disabled+0x3d/0xf2\n ? lock_is_held_type+0xbe/0xfd\n rtnetlink_rcv_msg+0x23f/0x26a\n ? check_preemption_disabled+0x3d/0xf2\n ? rtnl_calcit.isra.0+0x147/0x147\n netlink_rcv_skb+0x61/0xb2\n netlink_unicast+0x100/0x187\n netlink_sendmsg+0x37f/0x3a0\n ? netlink_unicast+0x187/0x187\n sock_sendmsg_nosec+0x67/0x9b\n ____sys_sendmsg+0x19d/0x1f9\n ? copy_msghdr_from_user+0x4c/0x5e\n ? rcu_read_lock_any_held+0x2a/0x78\n ___sys_sendmsg+0x6c/0x8c\n ? asm_sysvec_apic_timer_interrupt+0x12/0x20\n ? lockdep_hardirqs_on+0xd9/0x102\n ? sockfd_lookup_light+0x69/0x99\n __sys_sendmsg+0x50/0x6e\n do_syscall_64+0xcb/0xf2\n entry_SYSCALL_64_after_hwframe+0x44/0xae\n RIP: 0033:0x7f98dea28914\n Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b5 0f 1f 80 00 00 00 00 48 8d 05 e9 5d 0c 00 8b 00 85 c0 75 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 41 54 41 89 d4 55 48 89 f5 53\n RSP: 002b:00007fff859f5e68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e2e\n RAX: ffffffffffffffda RBX: 00000000619cb810 RCX: 00007f98dea28914\n RDX: 0000000000000000 RSI: 00007fff859f5ed0 RDI: 0000000000000003\n RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000008\n R10: fffffffffffffce6 R11: 0000000000000246 R12: 0000000000000001\n R13: 000055c0097ae520 R14: 000055c0097957fd R15: 00007fff859f63a0\n </TASK>\n Modules linked in: bridge stp llc bonding virtio_net"}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net: nexthop: corrige la desreferencia del puntero nulo cuando IPv6 no est\u00e1 habilitado Cuando intentamos agregar un nexthop IPv6 y IPv6 no est\u00e1 habilitado (!CONFIG_IPV6) alcanzaremos una desreferencia del puntero NULL [1] en la ruta de error de nh_create_ipv6() debido a la llamada a ipv6_stub-&gt;fib6_nh_release. El error ha estado presente desde el comienzo del soporte de la puerta de enlace IPv6 nexthop. El commit 1aefd3de7bc6 (\"ipv6: Agregar fib6_nh_init y liberar a los stubs\") nos dice que solo fib6_nh_init tiene un stub ficticio porque no se debe llamar a fib6_nh_release si fib6_nh_init devuelve un error, pero el commit a continuaci\u00f3n agreg\u00f3 una llamada a ipv6_stub-&gt;fib6_nh_release en su error camino. Para solucionarlo, devuelva el error -EAFNOSUPPORT del c\u00f3digo auxiliar ficticio directamente sin llamar a ipv6_stub-&gt;fib6_nh_release en la ruta de error de nh_create_ipv6(). [1] La salida est\u00e1 un poco truncada, pero muestra claramente el error. ERROR: desreferencia del puntero NULL del kernel, direcci\u00f3n: 0000000000000000000 #PF: b\u00fasqueda de instrucciones del supervisor en modo kernel #PF: c\u00f3digo_error(0x0010) - p\u00e1gina no presente PGD 0 P4D 0 Ups: 0010 [#1] PREEMPT SMP NOPTI CPU: 4 PID: 638 Comm: ip Kdump: cargado No contaminado 5.16.0-rc1+ #446 Nombre del hardware: PC est\u00e1ndar QEMU (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 01/04/2014 RIP: 0010:0x0 C\u00f3digo: No se puede acceder a los bytes del c\u00f3digo de operaci\u00f3n en RIP 0xffffffffffffffd6. RSP: 0018:ffff888109f5b8f0 EFLAGS: 00010286^Ac RAX: 0000000000000000 RBX: ffff888109f5ba28 RCX: 00000000000000000 RDX: 0000000000000000 RSI: 000000000000000 RDI: ffff8881008a2860 RBP: ffff888109f5b9d8 R08: 0000000000000000 R09: 00000000000000000 R10: ffff888109f5b978 R11: 9f5b948 R12: 00000000ffffff9f R13: ffff8881008a2a80 R14 : ffff8881008a2860 R15: ffff8881008a2840 FS: 00007f98de70f100(0000) GS:ffff88822bf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000100efc000 CR4: 00000000000006e0 Seguimiento de llamadas: nh_create_ipv6+0xed /0x10c rtm_new_nexthop+0x6d7/0x13f3 ? check_preemption_disabled+0x3d/0xf2? lock_is_held_type+0xbe/0xfd rtnetlink_rcv_msg+0x23f/0x26a? check_preemption_disabled+0x3d/0xf2? rtnl_calcit.isra.0+0x147/0x147 netlink_rcv_skb+0x61/0xb2 netlink_unicast+0x100/0x187 netlink_sendmsg+0x37f/0x3a0 ? netlink_unicast+0x187/0x187 sock_sendmsg_nosec+0x67/0x9b ____sys_sendmsg+0x19d/0x1f9 ? copy_msghdr_from_user+0x4c/0x5e? rcu_read_lock_any_held+0x2a/0x78 ___sys_sendmsg+0x6c/0x8c? asm_sysvec_apic_timer_interrupt+0x12/0x20? lockdep_hardirqs_on+0xd9/0x102? sockfd_lookup_light+0x69/0x99 __sys_sendmsg+0x50/0x6e do_syscall_64+0xcb/0xf2 Entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f98dea28914 C\u00f3digo: 00 f7 d8 64 89 02 c7 c0 ff ff ff ff eb b5 0f 1f 80 00 00 00 00 48 8d 05 e9 5d 0c 00 8b 00 85 c0 75 13 b8 2e 00 00 00 0f 05 &lt;48&gt; 3d 00 f0 ff ff 77 54 c3 0f 1f 00 41 54 41 89 d4 55 48 89 f5 53 RSP: :00007fff859f5e68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e2e RAX: ffffffffffffffda RBX: 00000000619cb810 RCX: 00007f98dea28914 RDX: 0000000000000000 RSI: 00007fff859f5ed0 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000008 R10: fffffffffffffce6 R11: 0000000000000246 R12: 0000000000001 R13: 000055c0097ae520 R14: 000055c0097957fd R15: 00007fff859f63a0 &lt; /TASK&gt; M\u00f3dulos vinculados en: bridge stp llc bonding virtio_net"}], "lastModified": "2024-06-10T19:22:05.237", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "755F3E83-05A5-403D-A6B2-ED9DE8B0F69B", "versionEndExcluding": "5.4.163", "versionStartIncluding": "5.3"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D4843826-EA9A-472B-82EC-B9E4FD4149AD", "versionEndExcluding": "5.10.83", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "990C08FB-0121-4296-896F-556312F8FF3B", "versionEndExcluding": "5.15.6", "versionStartIncluding": "5.11"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}