UBUNTU-CVE-2026-74695: Medium severity ubuntu/linux-hwe-edge vulnerability
In the Linux kernel, the following vulnerability has been resolved: netfilter: nfflowtable: drop existing skb dst before skbdstsetnoref() Incoming skbs passing through netfilter flowtable offload hooks (or XFRM offload path) might already carry a ref-counted dstentry assigned during earlier RX or routing steps. Calling skbdstsetnoref() when skb already holds a ref-counted dst overwrites skb->skbrefdst, leaking the previous dstentry reference count and triggering a DEBUGNETWARNONONCE assertion in skbdstcheckunset(): WARNING: at skbdstcheckunset include/linux/skbuff.h:1170 WARNING: at skbdstsetnoref include/linux/skbuff.h:1234 WARNING: at nfflowoffloadiphook+0xf6c/0x2b60 net/netfilter/nfflowtableip.c:864 Drop any existing dstentry reference with skbdstdrop(skb) before setting the non-referenced flowtable destination.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 6.8.0-1036.39 - Compensating control
In the netfilter flowtable offload and XFRM offload paths, call skb_dst_drop(skb) to release any existing ref-counted dst_entry before calling skb_dst_set_noref().