Tracker / CVE-2025-38732
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.
Affected products and versions
| debian | debian_linux |
|---|---|
| linux | linux_kernel |
| linux | linux_kernel · 5.11 → 5.15.190 |
| linux | linux_kernel · 5.16 → 6.1.149 |
| linux | linux_kernel · 5.9 → 5.10.241 |
| linux | linux_kernel · 6.13 → 6.16.4 |
| linux | linux_kernel · 6.2 → 6.6.103 |
| linux | linux_kernel · 6.7 → 6.12.44 |