{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38192", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:23.993Z", "datePublished": "2025-07-04T13:37:16.642Z", "dateUpdated": "2026-08-05T12:00:17.069Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:00:17.069Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: clear the dst when changing skb protocol\n\nA not-so-careful NAT46 BPF program can crash the kernel\nif it indiscriminately flips ingress packets from v4 to v6:\n\n BUG: kernel NULL pointer dereference, address: 0000000000000000\n ip6_rcv_core (net/ipv6/ip6_input.c:190:20)\n ipv6_rcv (net/ipv6/ip6_input.c:306:8)\n process_backlog (net/core/dev.c:6186:4)\n napi_poll (net/core/dev.c:6906:9)\n net_rx_action (net/core/dev.c:7028:13)\n do_softirq (kernel/softirq.c:462:3)\n netif_rx (net/core/dev.c:5326:3)\n dev_loopback_xmit (net/core/dev.c:4015:2)\n ip_mc_finish_output (net/ipv4/ip_output.c:363:8)\n NF_HOOK (./include/linux/netfilter.h:314:9)\n ip_mc_output (net/ipv4/ip_output.c:400:5)\n dst_output (./include/net/dst.h:459:9)\n ip_local_out (net/ipv4/ip_output.c:130:9)\n ip_send_skb (net/ipv4/ip_output.c:1496:8)\n udp_send_skb (net/ipv4/udp.c:1040:8)\n udp_sendmsg (net/ipv4/udp.c:1328:10)\n\nThe output interface has a 4->6 program attached at ingress.\nWe try to loop the multicast skb back to the sending socket.\nIngress BPF runs as part of netif_rx(), pushes a valid v6 hdr\nand changes skb->protocol to v6. We enter ip6_rcv_core which\ntries to use skb_dst(). But the dst is still an IPv4 one left\nafter IPv4 mcast output.\n\nClear the dst in all BPF helpers which change the protocol.\nTry to preserve metadata dsts, those may carry non-routing\nmetadata." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The stale dst only survives to the ingress BPF hook on locally generated traffic (loopback_xmit's skb_dst_force, or ip_mc_output's dev_loopback_xmit); packets received from the wire have skb_dst == NULL at sch_handle_ingress, so there is no remote trigger. The attacker must be a local user sending packets from a socket.\nAC:L - Triggering is fully deterministic — a single sendto() to a multicast group with the default IP_MULTICAST_LOOP, or to a local address over lo, reaches the ingress BPF hook with a live IPv4 dst attached. No race, timing window, or unpredictable state is involved.\nPR:L - On a system running a legitimate NAT46/NAT64 tc-BPF program (Android CLAT, Cilium NAT46/64), an ordinary unprivileged user needs nothing beyond an unprivileged UDP socket to generate the looped-back traffic that hits the bug. No capability is required for the triggering action itself.\nUI:N - The attacker generates the triggering packet entirely on their own via a socket send; no victim action, mount, or file open is needed.\nS:U - The corruption and its consequences are confined to the kernel's own memory and networking state within the same security authority. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - ip6_dst_idev() reads rt6i_idev at dst+72 from a 192-byte rtable slab object, an out-of-bounds read into the adjacent object, and the resulting ifindex is stored in IP6CB(skb)->iif and copied to userspace as ipi6_ifindex via IPV6_PKTINFO, yielding a kernel-memory disclosure primitive on top of the type confusion.\nI:H - ip6_rcv_finish() skips the IPv6 route lookup and dst_input() dispatches the IPv4 input handler on an IPv6 skb (and vice versa), a cross-family type confusion in which skb_rtable()->rt_iif and ->rt_flags are read out of rt6_info's address/pointer fields and steer socket demultiplexing and delivery decisions.\nA:H - The confirmed result is a NULL/wild pointer dereference inside ip6_rcv_core() executing in softirq context, producing an immediate kernel oops or panic that any unprivileged user can trigger repeatedly." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/core/filter.c" ], "versions": [ { "version": "6578171a7ff0c31dc73258f93da7407510abf085", "lessThan": "a046f183d21ab5ace5a96ece4cf9873a42f003a7", "status": "affected", "versionType": "git" }, { "version": "6578171a7ff0c31dc73258f93da7407510abf085", "lessThan": "98b1d8dc9a3170b2614f1e8c93854e75cdd83980", "status": "affected", "versionType": "git" }, { "version": "6578171a7ff0c31dc73258f93da7407510abf085", "lessThan": "bfa4d86e130a09f67607482e988313430e38f6c4", "status": "affected", "versionType": "git" }, { "version": "6578171a7ff0c31dc73258f93da7407510abf085", "lessThan": "2a3ad42a57b43145839f2f233fb562247658a6d9", "status": "affected", "versionType": "git" }, { "version": "6578171a7ff0c31dc73258f93da7407510abf085", "lessThan": "e9994e7b9f7bbb882d13c8191731649249150d21", "status": "affected", "versionType": "git" }, { "version": "6578171a7ff0c31dc73258f93da7407510abf085", "lessThan": "ba9db6f907ac02215e30128770f85fbd7db2fcf9", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/core/filter.c" ], "versions": [ { "version": "4.8", "status": "affected" }, { "version": "0", "lessThan": "4.8", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.209", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.167", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.95", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.35", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15.4", "lessThanOrEqual": "6.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "5.15.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "6.1.167" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "6.6.95" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "6.12.35" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "6.15.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "6.16" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a046f183d21ab5ace5a96ece4cf9873a42f003a7" }, { "url": "https://git.kernel.org/stable/c/98b1d8dc9a3170b2614f1e8c93854e75cdd83980" }, { "url": "https://git.kernel.org/stable/c/bfa4d86e130a09f67607482e988313430e38f6c4" }, { "url": "https://git.kernel.org/stable/c/2a3ad42a57b43145839f2f233fb562247658a6d9" }, { "url": "https://git.kernel.org/stable/c/e9994e7b9f7bbb882d13c8191731649249150d21" }, { "url": "https://git.kernel.org/stable/c/ba9db6f907ac02215e30128770f85fbd7db2fcf9" } ], "title": "net: clear the dst when changing skb protocol", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-07-14T12:41:36.573Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": 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"unknown" } ], "references": [ { "url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html" }, { "url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html" } ] } ] } }