CVE-2026-64189

In the Linux kernel, the following vulnerability has been resolved:

netfilter: ipset: fix race between dump and ip_set_list resize

The release path of ip_set_dump_do() and ip_set_dump_done() read

inst->ip_set_list via ip_set_ref_netlink(), a plain rcu_dereference_raw()

of the array pointer. These run from netlink_recvmsg() without the nfnl

mutex and without an RCU read-side critical section.

A concurrent ip_set_create() can grow the array: it publishes the new

array, calls synchronize_net() and then kvfree()s the old one. Since the

dump paths read the array outside any RCU reader, synchronize_net() does

not wait for them and the old array can be freed while they still index

into it, causing a use-after-free.

The dumped set itself stays pinned via set->ref_netlink, so only the

array load needs protecting. Take rcu_read_lock() around it, matching

ip_set_get_byname() and __ip_set_put_byindex().

BUG: KASAN: slab-use-after-free in ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1697)

Read of size 8 at addr ffff88800b5c4018 by task exploit/150

Call Trace:

...

kasan_report (mm/kasan/report.c:595)

ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1697)

netlink_dump (net/netlink/af_netlink.c:2325)

netlink_recvmsg (net/netlink/af_netlink.c:1976)

sock_recvmsg (net/socket.c:1159)

__sys_recvfrom (net/socket.c:2315)

...

Oops: general protection fault, probably for non-canonical address ... KASAN NOPTI

KASAN: maybe wild-memory-access in range [0x02d6...d0-0x02d6...d7]

RIP: 0010:ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1698)

Kernel panic - not syncing: Fatal exception