{"id":"AZL-73935","summary":"CVE-2025-38732 affecting package kernel for versions less than 5.15.200.1-1","details":"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/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.","modified":"2026-04-01T05:22:21.743437Z","published":"2025-09-05T18:15:42Z","upstream":["CVE-2025-38732"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-38732"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:2","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.15.200.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-73935.json"}}],"schema_version":"1.7.5"}