Answer in brief
CVE-2026-64572 records a Unknown severity vulnerability in ipv4: fib: free fib_alias with kfree_rcu() on insert error path. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=a6c76c17df021b141b0d306828c9fe4ba2d2717c <8150b5365f026e72250cacc527ea00be30f40105 || >=a6c76c17df021b141b0d306828c9fe4ba2d2717c <d007056868723de9c0cc3f5ffaad47a8d468b9a4 || >=a6c76c17df021b141b0d306828c9fe4ba2d2717c <cb8be318b4432abd88d3172ec157330f27a5f7a7 || >=a6c76c17df021b141b0d306828c9fe4ba2d2717c <b8d2ea75c76abcd0d72679c2f488271f573e32fb || >=a6c76c17df021b141b0d306828c9fe4ba2d2717c <f2f152e94a67bc746afaf05a1b2702c195553112 | 8150b5365f026e72250cacc527ea00be30f40105, d007056868723de9c0cc3f5ffaad47a8d468b9a4, cb8be318b4432abd88d3172ec157330f27a5f7a7, b8d2ea75c76abcd0d72679c2f488271f573e32fb, f2f152e94a67bc746afaf05a1b2702c195553112 |
| Linux/Linuxgeneric | 5.6 | Not reported |
| Linux/Linuxgeneric | >=a6c76c17df021b141b0d306828c9fe4ba2d2717c <9d0778571def598c31e84a38ae5a7ebc6f65e6d8 || >=a6c76c17df021b141b0d306828c9fe4ba2d2717c <bb03350f974aec352b660d032a1d283eb462165a || >=a6c76c17df021b141b0d306828c9fe4ba2d2717c <6429c9cfd941e62acd7bb0bc64d631574d4c3b2a || >=a6c76c17df021b141b0d306828c9fe4ba2d2717c <8150b5365f026e72250cacc527ea00be30f40105 || >=a6c76c17df021b141b0d306828c9fe4ba2d2717c <d007056868723de9c0cc3f5ffaad47a8d468b9a4 || >=a6c76c17df021b141b0d306828c9fe4ba2d2717c <cb8be318b4432abd88d3172ec157330f27a5f7a7 || >=a6c76c17df021b141b0d306828c9fe4ba2d2717c <b8d2ea75c76abcd0d72679c2f488271f573e32fb || >=a6c76c17df021b141b0d306828c9fe4ba2d2717c <f2f152e94a67bc746afaf05a1b2702c195553112 | 9d0778571def598c31e84a38ae5a7ebc6f65e6d8, bb03350f974aec352b660d032a1d283eb462165a, 6429c9cfd941e62acd7bb0bc64d631574d4c3b2a, 8150b5365f026e72250cacc527ea00be30f40105, d007056868723de9c0cc3f5ffaad47a8d468b9a4, cb8be318b4432abd88d3172ec157330f27a5f7a7, b8d2ea75c76abcd0d72679c2f488271f573e32fb, f2f152e94a67bc746afaf05a1b2702c195553112 |
Published upstream
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: ipv4: fib: free fib_alias with kfree_rcu() on insert error path fib_table_insert() publishes new_fa into the leaf's fa_list with fib_insert_alias() before calling the fib entry notifiers. When a notifier fails, the error path removes new_fa with fib_remove_alias() (hlist_del_rcu) and frees it right away with kmem_cache_free(). fib_table_lookup() walks that list under rcu_read_lock() only, so a concurrent lookup that already reached new_fa keeps reading it after the free: BUG: KASAN: slab-use-after-free in fib_table_lookup (net/ipv4/fib_trie.c:1601) Read of size 1 at addr ffff88810676d4eb by task exploit/297 Call Trace: fib_table_lookup (net/ipv4/fib_trie.c:1601) ip_route_output_key_hash_rcu (net/ipv4/route.c:2814) ip_route_output_key_hash (net/ipv4/route.c:2705) __ip4_datagram_connect (net/ipv4/datagram.c:49) udp_connect (net/ipv4/udp.c:2144) __sys_connect (net/socket.c:2167) __x64_sys_connect (net/socket.c:2173) do_syscall_64 entry_SYSCALL_64_after_hwframe which belongs to the cache ip_fib_alias of size 56 Triggering the error path needs CAP_NET_ADMIN and a registered fib notifier that can reject a route; a netdevsim device whose IPv4 FIB resource is exhausted is enough. Free new_fa with alias_free_mem_rcu(), as fib_table_delete() already does for a fib_alias removed from the trie.
Quoted source text, attributed separately from HOL analysis.