Executive brief
A vulnerability in the Linux kernel's memory management component can cause a system to crash during its initial startup process. This occurs if specific configuration settings (hugepages) are entered incorrectly in the system's boot instructions. While this primarily affects system availability by preventing a successful boot, it requires the ability to modify boot parameters, typically through physical access or administrative control.
Technical details
A NULL pointer dereference exists in the hugetlb_add_param() function within mm/hugetlb.c. When kernel boot parameters such as 'hugepages', 'hugepagesz', or 'default_hugepagesz' are provided without an '=' separator, the early parameter parsing logic passes a NULL pointer to hugetlb_add_param(). The function subsequently calls strlen() on this NULL pointer, resulting in a kernel panic during the early boot phase. The fix introduces a check to reject NULL values and return -EINVAL. This vulnerability is primarily a local denial-of-service during boot, as it requires the ability to modify the kernel command line.
Affected products
- Linux Linux kernel All versions prior to the fix in mm/hugetlb.c
Timeline
- 2026-04-09: disclosed: Initial patch submitted by Thorsten Blum
- 2026-06-08: advisory: CVE-2026-46284 published