Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_flow_table: drop existing skb dst before skb_dst_set_noref() Incoming skbs passing through netfilter flowtable offload hooks (or XFRM offload path) might already carry a ref-counted dst_entry assigned during earlier RX or routing steps. Calling skb_dst_set_noref() when skb already holds a ref-counted dst overwrites skb->_skb_refdst, leaking the previous dst_entry reference count and triggering a DEBUG_NET_WARN_ON_ONCE assertion in skb_dst_check_unset(): WARNING: at skb_dst_check_unset include/linux/skbuff.h:1170 WARNING: at skb_dst_set_noref include/linux/skbuff.h:1234 WARNING: at nf_flow_offload_ip_hook+0xf6c/0x2b60 net/netfilter/nf_flow_table_ip.c:864 Drop any existing dst_entry reference with skb_dst_drop(skb) before setting the non-referenced flowtable destination.
References6
- git.kernel.org/stable/c/12afa450a6a6c0cce2c42b7545a9958f62d8a00c
- git.kernel.org/stable/c/274f544a32c08638ee887f2e27e3235b6b1237d4
- git.kernel.org/stable/c/4db3b48a966ed479b99cc8319ea9e46d4f7c703b
- git.kernel.org/stable/c/538e67e8c7889cf5f93951f5309d1bcb41f86036
- git.kernel.org/stable/c/763f59b72ddaf18d0750d53083a74355f6c003c8
- git.kernel.org/stable/c/8aecf0bbcc72605592134c917c222207d8f63ab0
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 0% percentile: 42 · as of 9 November 2026
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