{"id":"CVE-2025-38732","title":"netfilter: nf_reject: don't leak dst refcount for loopback packets","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_reject: don't leak dst refcount for loopback packets\n\nrecent patches to add a WARN() when replacing skb dst entry found an\nold bug:\n\nWARNING: include/linu…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= f53b9b0bdc59c0823679f2e3214e0d538f5951b9 < 7b8b503c06274ef3c6c1a107743f1ec0d0a53ef8","Linux >= f53b9b0bdc59c0823679f2e3214e0d538f5951b9 < 82ef97abf22790182f7d433c74960dfd61b99c33","Linux >= f53b9b0bdc59c0823679f2e3214e0d538f5951b9 < b7a885ba25960c91db237c3f83b4285156789bce","Linux >= f53b9b0bdc59c0823679f2e3214e0d538f5951b9 < a0a3ace2a57887dac1e7c9a724846040c3e31868","Linux >= f53b9b0bdc59c0823679f2e3214e0d538f5951b9 < 51e8531371f90bee742c63775c9a568e5d6bf3c5","Linux >= f53b9b0bdc59c0823679f2e3214e0d538f5951b9 < b32e1590a8d22cf7d7f965e46d5576051acf8e42","Linux >= f53b9b0bdc59c0823679f2e3214e0d538f5951b9 < 91a79b792204313153e1bdbbe5acbfc28903b3a5","Linux 5.9"],"published":"2025-09-05","updated":"2026-09-08","sourceUpdated":"2026-09-08T08:42:03.055Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-38732","references":[{"url":"https://git.kernel.org/stable/c/7b8b503c06274ef3c6c1a107743f1ec0d0a53ef8"},{"url":"https://git.kernel.org/stable/c/82ef97abf22790182f7d433c74960dfd61b99c33"},{"url":"https://git.kernel.org/stable/c/b7a885ba25960c91db237c3f83b4285156789bce"},{"url":"https://git.kernel.org/stable/c/a0a3ace2a57887dac1e7c9a724846040c3e31868"},{"url":"https://git.kernel.org/stable/c/51e8531371f90bee742c63775c9a568e5d6bf3c5"},{"url":"https://git.kernel.org/stable/c/b32e1590a8d22cf7d7f965e46d5576051acf8e42"},{"url":"https://git.kernel.org/stable/c/91a79b792204313153e1bdbbe5acbfc28903b3a5"}],"tags":["cve.org"],"epss":0.00172,"epssPercentile":0.069,"ingestedAt":"2026-09-08T15:33:26.997Z","slug":"CVE-2025-38732","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_reject: don't leak dst refcount for loopback packets\n\nrecent patches to add a WARN() when replacing skb dst entry found an\nold bug:\n\nWARNING: include/linux/skbuff.h:1165 skb_dst_check_unset include/linux/skbuff.h:1164 [inline]\nWARNING: include/linux/skbuff.h:1165 skb_dst_set include/linux/skbuff.h:1210 [inline]\nWARNING: include/linux/skbuff.h:1165 nf_reject_fill_skb_dst+0x2a4/0x330 net/ipv4/netfilter/nf_reject_ipv4.c:234\n[..]\nCall Trace:\n nf_send_unreach+0x17b/0x6e0 net/ipv4/netfilter/nf_reject_ipv4.c:325\n nft_reject_inet_eval+0x4bc/0x690 net/netfilter/nft_reject_inet.c:27\n expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]\n ..\n\nThis is because blamed commit forgot about loopback packets.\nSuch packets already have a dst_entry attached, even at PRE_ROUTING stage.\n\nInstead of checking hook just check if the skb already has a route\nattached to it.\n\n## Affected\n\n- `Linux >= f53b9b0bdc59c0823679f2e3214e0d538f5951b9 < 7b8b503c06274ef3c6c1a107743f1ec0d0a53ef8`\n- `Linux >= f53b9b0bdc59c0823679f2e3214e0d538f5951b9 < 82ef97abf22790182f7d433c74960dfd61b99c33`\n- `Linux >= f53b9b0bdc59c0823679f2e3214e0d538f5951b9 < b7a885ba25960c91db237c3f83b4285156789bce`\n- `Linux >= f53b9b0bdc59c0823679f2e3214e0d538f5951b9 < a0a3ace2a57887dac1e7c9a724846040c3e31868`\n- `Linux >= f53b9b0bdc59c0823679f2e3214e0d538f5951b9 < 51e8531371f90bee742c63775c9a568e5d6bf3c5`\n- `Linux >= f53b9b0bdc59c0823679f2e3214e0d538f5951b9 < b32e1590a8d22cf7d7f965e46d5576051acf8e42`\n- `Linux >= f53b9b0bdc59c0823679f2e3214e0d538f5951b9 < 91a79b792204313153e1bdbbe5acbfc28903b3a5`\n- `Linux 5.9`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}