{"id":"CVE-2025-38192","title":"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  BU…","summary":"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  BU…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-476"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 4.8, < 6.6.95","linux_kernel >= 6.7, < 6.12.35","linux_kernel >= 6.13, < 6.15.4","linux_kernel = 6.16"],"patched":["linux_kernel 6.15.4"],"published":"2025-07-04","updated":"2026-10-15","sourceUpdated":"2026-10-15T22:18:33.750","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-38192","references":[{"url":"https://git.kernel.org/stable/c/2a3ad42a57b43145839f2f233fb562247658a6d9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/98b1d8dc9a3170b2614f1e8c93854e75cdd83980","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a046f183d21ab5ace5a96ece4cf9873a42f003a7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ba9db6f907ac02215e30128770f85fbd7db2fcf9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bfa4d86e130a09f67607482e988313430e38f6c4","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e9994e7b9f7bbb882d13c8191731649249150d21","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-082556.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-457936.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-784472.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00203,"epssPercentile":0.10217,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-15T21:48:20.544494Z"},"ingestedAt":"2026-09-08T15:33:26.997Z","slug":"CVE-2025-38192","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `linux_kernel >= 4.8, < 6.6.95`\n- `linux_kernel >= 6.7, < 6.12.35`\n- `linux_kernel >= 6.13, < 6.15.4`\n- `linux_kernel = 6.16`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.15.4`","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}