CVE-2024-50045

{"id": "CVE-2024-50045", "cveTags": [], "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": "2024-10-21T20:15:17.373", "references": [{"url": "https://git.kernel.org/stable/c/3453f5839420bfbb85c86c61e49f49ffd0f041c4", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/75dfcb758015c97e1accd6340691fca67d363bed", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/78ed917133b118661e1fe62d4a85d5d428ee9568", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/915717e0bb9837cc5c101bc545af487bd787239e", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/95c0cff5a1a5d28bf623b92eb5d1a8f56ed30803", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/cce8419b8168f6e7eb637103a47f916f3de8bc81", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/f07131239a76cc10d5e82c19d91f53cb55727297", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/f9ff7665cd128012868098bbd07e28993e314fdb", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Modified", "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\nnetfilter: br_netfilter: fix panic with metadata_dst skb\n\nFix a kernel panic in the br_netfilter module when sending untagged\ntraffic via a VxLAN device.\nThis happens during the check for fragmentation in br_nf_dev_queue_xmit.\n\nIt is dependent on:\n1) the br_netfilter module being loaded;\n2) net.bridge.bridge-nf-call-iptables set to 1;\n3) a bridge with a VxLAN (single-vxlan-device) netdevice as a bridge port;\n4) untagged frames with size higher than the VxLAN MTU forwarded/flooded\n\nWhen forwarding the untagged packet to the VxLAN bridge port, before\nthe netfilter hooks are called, br_handle_egress_vlan_tunnel is called and\nchanges the skb_dst to the tunnel dst. The tunnel_dst is a metadata type\nof dst, i.e., skb_valid_dst(skb) is false, and metadata->dst.dev is NULL.\n\nThen in the br_netfilter hooks, in br_nf_dev_queue_xmit, there's a check\nfor frames that needs to be fragmented: frames with higher MTU than the\nVxLAN device end up calling br_nf_ip_fragment, which in turns call\nip_skb_dst_mtu.\n\nThe ip_dst_mtu tries to use the skb_dst(skb) as if it was a valid dst\nwith valid dst->dev, thus the crash.\n\nThis case was never supported in the first place, so drop the packet\ninstead.\n\nPING 10.0.0.2 (10.0.0.2) from 0.0.0.0 h1-eth0: 2000(2028) bytes of data.\n[ 176.291791] Unable to handle kernel NULL pointer dereference at\nvirtual address 0000000000000110\n[ 176.292101] Mem abort info:\n[ 176.292184] ESR = 0x0000000096000004\n[ 176.292322] EC = 0x25: DABT (current EL), IL = 32 bits\n[ 176.292530] SET = 0, FnV = 0\n[ 176.292709] EA = 0, S1PTW = 0\n[ 176.292862] FSC = 0x04: level 0 translation fault\n[ 176.293013] Data abort info:\n[ 176.293104] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000\n[ 176.293488] CM = 0, WnR = 0, TnD = 0, TagAccess = 0\n[ 176.293787] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0\n[ 176.293995] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000043ef5000\n[ 176.294166] [0000000000000110] pgd=0000000000000000,\np4d=0000000000000000\n[ 176.294827] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP\n[ 176.295252] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel veth\nbr_netfilter bridge stp llc ipv6 crct10dif_ce\n[ 176.295923] CPU: 0 PID: 188 Comm: ping Not tainted\n6.8.0-rc3-g5b3fbd61b9d1 #2\n[ 176.296314] Hardware name: linux,dummy-virt (DT)\n[ 176.296535] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS\nBTYPE=--)\n[ 176.296808] pc : br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter]\n[ 176.297382] lr : br_nf_dev_queue_xmit+0x2ac/0x4ec [br_netfilter]\n[ 176.297636] sp : ffff800080003630\n[ 176.297743] x29: ffff800080003630 x28: 0000000000000008 x27:\nffff6828c49ad9f8\n[ 176.298093] x26: ffff6828c49ad000 x25: 0000000000000000 x24:\n00000000000003e8\n[ 176.298430] x23: 0000000000000000 x22: ffff6828c4960b40 x21:\nffff6828c3b16d28\n[ 176.298652] x20: ffff6828c3167048 x19: ffff6828c3b16d00 x18:\n0000000000000014\n[ 176.298926] x17: ffffb0476322f000 x16: ffffb7e164023730 x15:\n0000000095744632\n[ 176.299296] x14: ffff6828c3f1c880 x13: 0000000000000002 x12:\nffffb7e137926a70\n[ 176.299574] x11: 0000000000000001 x10: ffff6828c3f1c898 x9 :\n0000000000000000\n[ 176.300049] x8 : ffff6828c49bf070 x7 : 0008460f18d5f20e x6 :\nf20e0100bebafeca\n[ 176.300302] x5 : ffff6828c7f918fe x4 : ffff6828c49bf070 x3 :\n0000000000000000\n[ 176.300586] x2 : 0000000000000000 x1 : ffff6828c3c7ad00 x0 :\nffff6828c7f918f0\n[ 176.300889] Call trace:\n[ 176.301123] br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter]\n[ 176.301411] br_nf_post_routing+0x2a8/0x3e4 [br_netfilter]\n[ 176.301703] nf_hook_slow+0x48/0x124\n[ 176.302060] br_forward_finish+0xc8/0xe8 [bridge]\n[ 176.302371] br_nf_hook_thresh+0x124/0x134 [br_netfilter]\n[ 176.302605] br_nf_forward_finish+0x118/0x22c [br_netfilter]\n[ 176.302824] br_nf_forward_ip.part.0+0x264/0x290 [br_netfilter]\n[ 176.303136] br_nf_forward+0x2b8/0x4e0 [br_netfilter]\n[ 176.303359] nf_hook_slow+0x48/0x124\n[ 176.303\n---truncated---"}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: netfilter: br_netfilter: fix panic with metadata_dst skb Corrige un p\u00e1nico del kernel en el m\u00f3dulo br_netfilter al enviar tr\u00e1fico sin etiquetar a trav\u00e9s de un dispositivo VxLAN. Esto sucede durante la comprobaci\u00f3n de fragmentaci\u00f3n en br_nf_dev_queue_xmit. Depende de: 1) que se est\u00e9 cargando el m\u00f3dulo br_netfilter; 2) que net.bridge.bridge-nf-call-iptables est\u00e9 establecido en 1; 3) que haya un puente con un netdevice VxLAN (single-vxlan-device) como puerto de puente; 4) que se hayan reenviado o inundado tramas sin etiquetar con un tama\u00f1o superior a la MTU de VxLAN. Al reenviar el paquete sin etiquetar al puerto de puente VxLAN, antes de que se llamen los ganchos de netfilter, se llama a br_handle_egress_vlan_tunnel y cambia skb_dst al dst del t\u00fanel. tunnel_dst es un tipo de metadatos de dst, es decir, skb_valid_dst(skb) es falso y metadata->dst.dev es NULL. Luego, en los ganchos br_netfilter, en br_nf_dev_queue_xmit, hay una verificaci\u00f3n de tramas que necesitan fragmentarse: las tramas con una MTU m\u00e1s alta que el dispositivo VxLAN terminan llamando a br_nf_ip_fragment, que a su vez llama a ip_skb_dst_mtu. ip_dst_mtu intenta usar skb_dst(skb) como si fuera un dst v\u00e1lido con dst->dev v\u00e1lido, de ah\u00ed el bloqueo. Este caso nunca fue compatible en primer lugar, por lo que descarta el paquete en su lugar. PING 10.0.0.2 (10.0.0.2) desde 0.0.0.0 h1-eth0: 2000(2028) bytes de datos. [ 176.291791] No se puede manejar la desreferencia del puntero NULL del n\u00facleo en la direcci\u00f3n virtual 0000000000000110 [ 176.292101] Informaci\u00f3n de aborto de memoria: [ 176.292184] ESR = 0x0000000096000004 [ 176.292322] EC = 0x25: DABT (EL actual), IL = 32 bits [ 176.292530] SET = 0, FnV = 0 [ 176.292709] EA = 0, S1PTW = 0 [ 176.292862] FSC = 0x04: error de traducci\u00f3n de nivel 0 [ 176.293013] Informaci\u00f3n de aborto de datos: [ 176.293104] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 [ 176.293488] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 176.293787] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 176.293995] pgtable del usuario: p\u00e1ginas de 4k, VA de 48 bits, pgdp=0000000043ef5000 [ 176.294166] [0000000000000110] pgd=000000000000000, p4d=0000000000000000 [ 176.294827] Error interno: Oops: 0000000096000004 [#1] PREEMPT SMP [ 176.295252] M\u00f3dulos vinculados: vxlan ip6_udp_tunnel udp_tunnel veth br_netfilter bridge stp llc ipv6 crct10dif_ce [ 176.295923] CPU: 0 PID: 188 Comm: ping No contaminado 6.8.0-rc3-g5b3fbd61b9d1 #2 [ 176.296314] Nombre del hardware: linux,dummy-virt (DT) [ 176.296535] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 176.296808] pc : br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter] [ 176.297382] lr : br_nf_dev_queue_xmit+0x2ac/0x4ec [br_netfilter] [ 176.297636] sp : ffff800080003630 [ 176.297743] x29: ffff800080003630 x28: 0000000000000008 x27: ffff6828c49ad9f8 [ 176.298093] x26: ffff6828c49ad000 x25: 0000000000000000 x24: 00000000000003e8 [ 176.298430] x23: 0000000000000000 x22: ffff6828c4960b40 x21: ffff6828c3b16d28 [ 176.298652] x20: ffff6828c3167048 x19: ffff6828c3b16d00 x18: 0000000000000014 [ 176.298926] x17: ffffb0476322f000 x16: ffffb7e164023730 x15: 0000000095744632 [ 176.299296] x14: ffff6828c3f1c880 x13: 0000000000000002 x12: ffffb7e137926a70 [ 176.299574] x11: 000000000000001 x10: ffff6828c3f1c898 x9: 0000000000000000 [ 176.300049] x8: ffff6828c49bf070 x7: 0008460f18d5f20e x6: f20e0100bebafeca [ 176.300302] x5 : ffff6828c7f918fe x4 : ffff6828c49bf070 x3 : 0000000000000000 [ 176.300586] x2 : 0000000000000000 x1 : ffff6828c3c7ad00 x0 : ffff6828c7f918f0 [ 176.300889] Rastreo de llamadas: [ 176.301123] br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter] [ 176.301411] br_nf_post_routing+0x2a8/0x3e4 [br_netfilter] [ 176.301703] br_nf_hook_slow+0x48/0x124 [ 176.302060] br_forward_finish+0xc8/0xe8 [puente] [ 176.302371] br_nf_hook_thresh+0x124/0x134 [br_filtro de red] [ 176.302605] br_nf_forward_finish+0x118/0x22c [br_filtro de red] [ 176.302824] br_nf_forward_ip.part.0+0x264/0x290 [br_filtro de red] [ 176.303136 ---truncado---"}], "lastModified": "2024-11-08T16:15:44.813", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E02B18E0-7618-4F55-A9D9-FC9A13DCDEEF", "versionEndExcluding": "5.10.227", "versionStartIncluding": "4.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4D51C05D-455B-4D8D-89E7-A58E140B864C", "versionEndExcluding": "5.15.168", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D01BD22E-ACD1-4618-9D01-6116570BE1EE", "versionEndExcluding": "6.1.113", "versionStartIncluding": "5.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "05D83DB8-7465-4F88-AFB2-980011992AC1", "versionEndExcluding": "6.6.57", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "AA84D336-CE9A-4535-B901-1AD77EC17C34", "versionEndExcluding": "6.11.4", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "7F361E1D-580F-4A2D-A509-7615F73167A1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.12:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "925478D0-3E3D-4E6F-ACD5-09F28D5DF82C"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}