CVE-2026-64189
Received Received - Intake

Race Condition in Linux Kernel Netfilter IPSet

Publication date: 2026-07-20

Last updated on: 2026-07-20

Assigner: kernel.org

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

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Meta Information

Published
2026-07-20
Last Modified
2026-07-20
Generated
2026-07-21
AI Q&A
2026-07-20
EPSS Evaluated
N/A
NVD
CVE-2026-64189
EUVD
EUVD-2026-46009

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
netfilter ipset *

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Exploitability

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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability is a race condition in the Linux kernel's netfilter ipset module. It occurs when the dump operation reads an array pointer without proper synchronization, while another operation concurrently resizes the array. This can lead to a use-after-free error when the old array is freed before the dump operation completes.

Detection Guidance

This vulnerability is specific to the Linux kernel's netfilter ipset module and requires kernel-level detection. Check if your kernel version includes the vulnerable code path by examining the ip_set_dump_do function in net/netfilter/ipset/ip_set_core.c. Use commands like 'uname -a' to check kernel version and 'dmesg | grep -i kasan' to look for slab-use-after-free errors.

Impact Analysis

This vulnerability could allow an attacker to cause a kernel panic or execute arbitrary code with kernel privileges. It may lead to system crashes, data corruption, or unauthorized access if exploited.

Compliance Impact

This vulnerability is a use-after-free flaw in the Linux kernel's netfilter ipset component. It does not directly relate to data protection or privacy compliance standards like GDPR or HIPAA, as it involves kernel memory corruption during network operations rather than unauthorized data access or exposure.

Mitigation Strategies

Apply the latest kernel patches that fix this issue. If patches are unavailable, consider disabling the ipset module temporarily using 'modprobe -r ip_set' or block netlink-based access to ipset functionality. Monitor kernel logs for exploitation attempts via 'dmesg -w'.

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