Executive brief
A vulnerability in the Linux kernel's LoongArch architecture support could allow a local user to cause a system crash or potentially gain unauthorized access. The issue stems from how the system handles specific hardware memory configurations (NUMA nodes). An exploit could disrupt business operations by causing server instability or compromising sensitive data stored on the affected system.
Technical details
A vulnerability was identified in the LoongArch architecture implementation within the Linux kernel. The root cause is the arch-specific definition of cpumask_of_node(), which did not account for the NUMA_NO_NODE constant (-1). When this valid but special index was passed to the function, it could lead to out-of-bounds memory access or improper CPU mask handling. A local attacker with low privileges could potentially exploit this to cause a denial of service (system crash) or execute arbitrary code with kernel privileges. The issue has been resolved by adding a check to return cpu_all_mask when NUMA_NO_NODE is encountered.
Affected products
- Linux Linux Kernel 5.19 to 6.1.165, 6.2 to 6.6.128, 6.7 to 6.12.75, 6.13 to 6.18.16, 6.19 to 6.19.6
Timeline
- 2026-05-06: disclosed
- 2026-05-06: advisory
- 2026-03-04: patched
References
- https://git.kernel.org/stable/c/1d8f2f024801019d85159a020b72a4424b46bcf4
- https://git.kernel.org/stable/c/61a56df2fbaad3a4d00f0c6a904b5d1ee8982eb4
- https://git.kernel.org/stable/c/92adfb707beec0fe956424373654a70aad35ea13
- https://git.kernel.org/stable/c/94b0c831eda778ae9e4f2164a8b3de485d8977bb
- https://git.kernel.org/stable/c/b5bf05e05cdf489a04137e4da407de9d4cca5295
- https://git.kernel.org/stable/c/bb1a54f7f011f19ed936632698eae574e0b91063