CVE-2026-64189netfilter: ipset: fix race between dump and ip_set_list resize

Official description

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

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/a7a299277959683204d73333c32c092fd69327d4
• https://git.kernel.org/stable/c/1bc67c3fc98e9fc07032cc56afcdbc690c47d11e
• https://git.kernel.org/stable/c/e8a9976b61f1bc4aa7fd25fa26726dfdf2adf710
• https://git.kernel.org/stable/c/96fbafc20ebd9a613736c2998b89c539fe3042f5
• https://git.kernel.org/stable/c/ff86ea9b7fdf70564e60436fbee68c96bc459943
• https://git.kernel.org/stable/c/81d54c766337b923eec26da0a13406760b091093
• https://git.kernel.org/stable/c/e8ee198bbc04a32d336e79160fde980e0235b39f
• https://git.kernel.org/stable/c/7cd9103283b26b917360ec99d7d2f2d761bcf1ab