Description
In the Linux kernel, the following vulnerability has been resolved: locking/csd_lock: Change csdlock_debug from early_param to __setup The csdlock_debug kernel-boot parameter is parsed by the early_param() function csdlock_debug(). If set, csdlock_debug() invokes static_branch_enable() to enable csd_lock_wait feature, which triggers a panic on arm64 for kernels built with CONFIG_SPARSEMEM=y and CONFIG_SPARSEMEM_VMEMMAP=n. With CONFIG_SPARSEMEM_VMEMMAP=n, __nr_to_section is called in static_key_enable() and returns NULL, resulting in a NULL dereference because mem_section is initialized only later in sparse_init(). This is also a problem for powerpc because early_param() functions are invoked earlier than jump_label_init(), also resulting in static_key_enable() failures. These failures cause the warning "static key 'xxx' used before call to jump_label_init()". Thus, early_param is too early for csd_lock_wait to run static_branch_enable(), so changes it to __setup to fix these.
Affected products
linux: linux kernel
References4
Metrics
- CVSS 3.1
-
5.5
MEDIUM
Score source: NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 0% percentile: 17 · as of 7 November 2026
- CWE
- CWE-476
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