CVE-2024-50133: LoongArch: Don't crash in stack_top() for tasks without vDSO

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-11-05 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: LoongArch: Don't crash in stack_top() for tasks without vDSO Not all tasks have a vDSO mapped, for example kthreads never do. If such a task ever ends up calling stack_top(), it will derefence the NULL vdso pointer and crash. This can for example happen when using kunit: [<9000000000203874>] stack_top+0x58/0xa8 [<90000000002956cc>] arch_pick_mmap_layout+0x164/0x220 [<90000000003c284c>] kunit_vm_mmap_init+0x108/0x12c [<90000000003c1fbc>] __kunit_add_resource+0x38/0x8c [<90000000003c2704>] kunit_vm_mmap+0x88/0xc8 [<9000000000410b14>] usercopy_test_init+0xbc/0x25c [<90000000003c1db4>] kunit_try_run_case+0x5c/0x184 [<90000000003c3d54>] kunit_generic_run_threadfn_adapter+0x24/0x48 [<900000000022e4bc>] kthread+0xc8/0xd4 [<9000000000200ce8>] ret_from_kernel_thread+0xc/0xa4

Affected products

Linux kernel: from 5.19 before 6.1.115; from 6.2 before 6.6.59; from 6.7 before 6.11.6; 6.12-rc1, 6.12-rc2, 6.12-rc3, 6.12-rc4 — fixed in 6.1.115, 6.11.6, 6.6.59

How to fix

Upgrade to a fixed version: Linux kernel 6.1.115, 6.11.6, 6.6.59. Check the vendor advisory for mitigations.

References

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