CVE-2026-53219
Published: June 27, 2026Last modified: July 6, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: x_tables: avoid leaking percpu counter pointers The native and compat get-entries paths copy the fixed rule entry header from the kernelized rule blob to userspace before overwriting the entry's counter fields with a sanitized counter snapshot. On SMP kernels, entry->counters.pcnt contains the percpu allocation address used by x_tables rule counters. A caller can provide a userspace buffer that faults during the initial fixed-header copy after pcnt has been copied but before the later sanitized counter copy runs. The syscall then returns -EFAULT while leaving the raw percpu pointer in userspace. Copy only the fixed entry prefix before counters from the kernelized rule blob, then copy the sanitized counter snapshot into the counter field. Apply this ordering to the IPv4, IPv6, and ARP native and compat get-entries implementations so a fault cannot expose the internal percpu counter pointer.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 5.5 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | NONE |
| Integrity impact | NONE |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Fixed (6.1.177-r0) |
| 25 LTS | linux-lts | Fixed (6.12.95-r0) | |
| Stream | linux-lts | Fixed (6.18.38-r0) |
References
- https://git.kernel.org/stable/c/08a3e218064db11f154ad9ad5541751ea7f34ebe
- https://git.kernel.org/stable/c/0b35dc8527ccc16b7dc34e8a3164313e68cd4e45
- https://git.kernel.org/stable/c/8d67e42ad3b1a95a152541015a07110e06992d6c
- https://git.kernel.org/stable/c/a0d16941adf3a501956d74aefd8d6e217906e79c
- https://git.kernel.org/stable/c/b28e2fcad3db7e8687b15bc20bced26b5b7c920e
- https://git.kernel.org/stable/c/b74ba3343eb44b2cbf7e9665918c287df1d52ebb
- https://git.kernel.org/stable/c/f7f2fbb0e893a0238dc464f8d8c0f5609bec584f
- https://git.kernel.org/stable/c/fb0521aff1e10e300d89725cc439d3ea74c828c5