Executive brief
A vulnerability was identified in the Linux kernel's networking subsystem, specifically within the netfilter component used for firewalling and network address translation. Under certain conditions, updating firewall rules while simultaneously viewing them could cause the system to behave unpredictably or crash. This issue primarily affects the stability of the system during administrative configuration changes.
Technical details
A race condition exists in the nf_tables component of the Linux kernel due to the use of non-RCU-safe list operations during the commit phase. Specifically, the code used list_splice() instead of list_splice_rcu() when publishing new hooks to basechains or flowtables. This could lead to inconsistent state or crashes when a netlink dump (list traversal) occurs concurrently with a ruleset update. The fix replaces list_splice() with list_splice_rcu() in net/netfilter/nf_tables_api.c to ensure RCU-safe traversal. This issue affects kernels from version 5.8 up to 7.1.
Affected products
- Linux Linux Kernel 5.8 to 7.1
Timeline
- 2026-04-15: disclosed: Initial patch authored
- 2026-05-23: patched: Patch committed to stable tree
- 2026-06-24: advisory: CVE published