CVE-2025-40260
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-12-04

Last updated on: 2025-12-04

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: sched_ext: Fix scx_enable() crash on helper kthread creation failure A crash was observed when the sched_ext selftests runner was terminated with Ctrl+\ while test 15 was running: NIP [c00000000028fa58] scx_enable.constprop.0+0x358/0x12b0 LR [c00000000028fa2c] scx_enable.constprop.0+0x32c/0x12b0 Call Trace: scx_enable.constprop.0+0x32c/0x12b0 (unreliable) bpf_struct_ops_link_create+0x18c/0x22c __sys_bpf+0x23f8/0x3044 sys_bpf+0x2c/0x6c system_call_exception+0x124/0x320 system_call_vectored_common+0x15c/0x2ec kthread_run_worker() returns an ERR_PTR() on failure rather than NULL, but the current code in scx_alloc_and_add_sched() only checks for a NULL helper. Incase of failure on SIGQUIT, the error is not handled in scx_alloc_and_add_sched() and scx_enable() ends up dereferencing an error pointer. Error handling is fixed in scx_alloc_and_add_sched() to propagate PTR_ERR() into ret, so that scx_enable() jumps to the existing error path, avoiding random dereference on failure.
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Meta Information
Published
2025-12-04
Last Modified
2025-12-04
Generated
2026-05-07
AI Q&A
2025-12-04
EPSS Evaluated
2026-05-05
NVD
EUVD
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability is a flaw in the Linux kernel's sched_ext component where a crash occurs due to improper error handling during helper kernel thread creation failure. Specifically, when the function kthread_run_worker() fails, it returns an error pointer instead of NULL, but the code only checks for NULL. This leads to dereferencing an error pointer and causes a crash when the sched_ext selftests runner is terminated with Ctrl+\ during a specific test. The fix involves properly handling the error pointer to avoid the crash.


How can this vulnerability impact me? :

This vulnerability can cause the Linux kernel to crash unexpectedly when certain tests or operations involving sched_ext are terminated improperly. Such crashes can lead to system instability, potential denial of service, and disruption of normal operations on affected systems.


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