In the Linux kernel, the following vulnerability has been resolved:
lwt: Fix return values of BPF xmit ops
BPF encap ops can return different types of positive values, such like
NET_RX_DROP, NET_XMIT_CN, NETDEV_TX_BUSY, and so on, from function
skb_do_redirect and bpf_lwt_xmit_reroute. At the xmit hook, such return
values would be treated implicitly as LWTUNNEL_XMIT_CONTINUE in
ip(6)_finish_output2. When this happens, skbs that have been freed would
continue to the neighbor subsystem, causing use-after-free bug and
kernel crashes.
To fix the incorrect behavior, skb_do_redirect return values can be
simply discarded, the same as tc-egress behavior. On the other hand,
bpf_lwt_xmit_reroute returns useful errors to local senders, e.g. PMTU
information. Thus convert its return values to avoid the conflict with
LWTUNNEL_XMIT_CONTINUE.
References
Configurations
Configuration 1 (hide)
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History
No history.
Information
Published : 2025-09-17 15:15
Updated : 2026-01-14 19:16
NVD link : CVE-2023-53338
Mitre link : CVE-2023-53338
CVE.ORG link : CVE-2023-53338
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-416
Use After Free
