CVE-2022-49990
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-06-18

Last updated on: 2025-11-14

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: s390: fix double free of GS and RI CBs on fork() failure The pointers for guarded storage and runtime instrumentation control blocks are stored in the thread_struct of the associated task. These pointers are initially copied on fork() via arch_dup_task_struct() and then cleared via copy_thread() before fork() returns. If fork() happens to fail after the initial task dup and before copy_thread(), the newly allocated task and associated thread_struct memory are freed via free_task() -> arch_release_task_struct(). This results in a double free of the guarded storage and runtime info structs because the fields in the failed task still refer to memory associated with the source task. This problem can manifest as a BUG_ON() in set_freepointer() (with CONFIG_SLAB_FREELIST_HARDENED enabled) or KASAN splat (if enabled) when running trinity syscall fuzz tests on s390x. To avoid this problem, clear the associated pointer fields in arch_dup_task_struct() immediately after the new task is copied. Note that the RI flag is still cleared in copy_thread() because it resides in thread stack memory and that is where stack info is copied.
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Meta Information
Published
2025-06-18
Last Modified
2025-11-14
Generated
2026-05-07
AI Q&A
2025-06-18
EPSS Evaluated
2026-05-05
NVD
CVE-2022-49990
Affected Vendors & Products
Showing 9 associated CPEs
Vendor Product Version / Range
linux linux_kernel 6.0
linux linux_kernel 6.0
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-415 The product calls free() twice on the same memory address.
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability is a double free issue in the Linux kernel on the s390 architecture. When a fork() system call fails after duplicating a task_struct but before completing the thread copy, the newly allocated task and its thread_struct memory are freed twice because pointers to guarded storage and runtime instrumentation control blocks still reference memory from the original task. This can cause kernel crashes or memory corruption.


How can this vulnerability impact me? :

This vulnerability can lead to kernel crashes or memory corruption on affected systems, potentially causing system instability or denial of service. It may manifest as BUG_ON() errors or KASAN splats during certain syscall fuzz testing on s390x systems.


What immediate steps should I take to mitigate this vulnerability?

To mitigate this vulnerability, update the Linux kernel to a version where the fix for the double free of GS and RI CBs on fork() failure on s390x architecture has been applied. This fix involves clearing the associated pointer fields in arch_dup_task_struct() immediately after the new task is copied. Additionally, enabling CONFIG_SLAB_FREELIST_HARDENED and KASAN can help detect related issues during testing.


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