CVE-2025-38732

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.
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:*

Configuration 2 (hide)

cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

History

19 Oct 2026, 21:10

Type Values Removed Values Added
Summary
  • (es) En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta: netfilter: nf_reject: no filtrar el contador de referencias dst para paquetes de loopback parches recientes para añadir un WARN() al reemplazar la entrada dst de skb encontraron un error antiguo: ADVERTENCIA: include/linux/skbuff.h:1165 skb_dst_check_unset include/linux/skbuff.h:1164 [en línea] ADVERTENCIA: include/linux/skbuff.h:1165 skb_dst_set include/linux/skbuff.h:1210 [en línea] ADVERTENCIA: include/linux/skbuff.h:1165 nf_reject_fill_skb_dst+0x2a4/0x330 net/ipv4/netfilter/nf_reject_ipv4.c:234 [..] Rastro de Llamada: 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 [en línea] .. Esto se debe a que el commit en cuestión olvidó los paquetes de loopback. Dichos paquetes ya tienen una entrada dst adjunta, incluso en la etapa PRE_ROUTING. En lugar de verificar el hook, simplemente verifica si el skb ya tiene una ruta adjunta a él.

15 Oct 2026, 02:17

Type Values Removed Values Added
References
  • () https://cert-portal.siemens.com/productcert/html/ssa-457936.html -

Information

Published : 2025-09-05 18:15

Updated : 2026-10-19 21:10


NVD link : CVE-2025-38732

Mitre link : CVE-2025-38732

CVE.ORG link : CVE-2025-38732


JSON object : View

Products Affected

debian

  • debian_linux

linux

  • linux_kernel