ghsa-p76p-fh7v-f8jw
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_reject: don't leak dst refcount for loopback packets
recent patches to add a WARN() when replacing skb dst entry found an old bug:
WARNING: include/linux/skbuff.h:1165 skb_dst_check_unset include/linux/skbuff.h:1164 [inline] WARNING: include/linux/skbuff.h:1165 skb_dst_set include/linux/skbuff.h:1210 [inline] WARNING: include/linux/skbuff.h:1165 nf_reject_fill_skb_dst+0x2a4/0x330 net/ipv4/netfilter/nf_reject_ipv4.c:234 [..] Call Trace: nf_send_unreach+0x17b/0x6e0 net/ipv4/netfilter/nf_reject_ipv4.c:325 nft_reject_inet_eval+0x4bc/0x690 net/netfilter/nft_reject_inet.c:27 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] ..
This is because blamed commit forgot about loopback packets. Such packets already have a dst_entry attached, even at PRE_ROUTING stage.
Instead of checking hook just check if the skb already has a route attached to it.
{
"affected": [],
"aliases": [
"CVE-2025-38732"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-09-05T18:15:42Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_reject: don\u0027t 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.",
"id": "GHSA-p76p-fh7v-f8jw",
"modified": "2025-09-05T18:31:25Z",
"published": "2025-09-05T18:31:25Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-38732"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/51e8531371f90bee742c63775c9a568e5d6bf3c5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7b8b503c06274ef3c6c1a107743f1ec0d0a53ef8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/82ef97abf22790182f7d433c74960dfd61b99c33"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/91a79b792204313153e1bdbbe5acbfc28903b3a5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a0a3ace2a57887dac1e7c9a724846040c3e31868"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b32e1590a8d22cf7d7f965e46d5576051acf8e42"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b7a885ba25960c91db237c3f83b4285156789bce"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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