netfilter: nf_reject: don't leak dst refcount for loopback packets

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2025-38732
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2025-09-05 18:15:42 UTC
Updated2026-05-12 13:17:03 UTC
DescriptionIn 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.

Risk And Classification

Primary CVSS: v3.1 5.5 MEDIUM from [email protected]

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Problem Types: NVD-CWE-Other

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Linux Linux Kernel All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected f53b9b0bdc59c0823679f2e3214e0d538f5951b9 7b8b503c06274ef3c6c1a107743f1ec0d0a53ef8 git Not specified
CNA Linux Linux affected f53b9b0bdc59c0823679f2e3214e0d538f5951b9 82ef97abf22790182f7d433c74960dfd61b99c33 git Not specified
CNA Linux Linux affected f53b9b0bdc59c0823679f2e3214e0d538f5951b9 b7a885ba25960c91db237c3f83b4285156789bce git Not specified
CNA Linux Linux affected f53b9b0bdc59c0823679f2e3214e0d538f5951b9 a0a3ace2a57887dac1e7c9a724846040c3e31868 git Not specified
CNA Linux Linux affected f53b9b0bdc59c0823679f2e3214e0d538f5951b9 51e8531371f90bee742c63775c9a568e5d6bf3c5 git Not specified
CNA Linux Linux affected f53b9b0bdc59c0823679f2e3214e0d538f5951b9 b32e1590a8d22cf7d7f965e46d5576051acf8e42 git Not specified
CNA Linux Linux affected f53b9b0bdc59c0823679f2e3214e0d538f5951b9 91a79b792204313153e1bdbbe5acbfc28903b3a5 git Not specified
CNA Linux Linux affected 5.9 Not specified
CNA Linux Linux unaffected 5.9 semver Not specified
CNA Linux Linux unaffected 5.10.241 5.10.* semver Not specified
CNA Linux Linux unaffected 5.15.190 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.149 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.103 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.44 6.12.* semver Not specified
CNA Linux Linux unaffected 6.16.4 6.16.* semver Not specified
CNA Linux Linux unaffected 6.17 * original_commit_for_fix Not specified
ADP Siemens SIMATIC CN 4100 affected V5.0 custom Not specified

References

ReferenceSourceLinkTags
lists.debian.org/debian-lts-announce/2025/10/msg00008.html af854a3a-2127-422b-91ae-364da2661108 lists.debian.org Mailing List, Third Party Advisory
git.kernel.org/stable/c/b7a885ba25960c91db237c3f83b4285156789bce 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/91a79b792204313153e1bdbbe5acbfc28903b3a5 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/7b8b503c06274ef3c6c1a107743f1ec0d0a53ef8 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/51e8531371f90bee742c63775c9a568e5d6bf3c5 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/82ef97abf22790182f7d433c74960dfd61b99c33 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/a0a3ace2a57887dac1e7c9a724846040c3e31868 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
cert-portal.siemens.com/productcert/html/ssa-032379.html 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e cert-portal.siemens.com
lists.debian.org/debian-lts-announce/2025/10/msg00007.html af854a3a-2127-422b-91ae-364da2661108 lists.debian.org Mailing List, Third Party Advisory
git.kernel.org/stable/c/b32e1590a8d22cf7d7f965e46d5576051acf8e42 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis
© CVE.report 2026 |

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report