CVE-2026-99224: Linux Vulnerability (CVSS 7)

Description

In the Linux kernel, the following vulnerability has been resolved: keys: Protect the type name while describing a key keyctl_describe_key() must keep the key type's name alive until kasprintf() has consumed it. The retained key reference keeps the key and its description alive, but does not pin the module providing its type. The name is passed to kasprintf() without holding key->sem. kvasprintf() uses the saved name pointer in two formatting passes, with a GFP_KERNEL allocation between them. With AF_RXRPC=m, a task that passes View permission before type retirement can overlap a privileged module unload in this order: 1. KEYCTL_DESCRIBE looks up the key, saves key->type->name in the kasprintf() arguments and completes the first formatting pass. 2. While the formatter is delayed before its second pass, af_rxrpc_exit() calls unregister_key_type(), which removes the type from the registry and waits for key_gc_keytype(). 3. The collector takes key->sem for writing, retypes the retained key to key_type_dead and completes retirement. Unregistration and module exit return, allowing free_module() to release the type and name. 4. The formatter resumes its second pass and reads the saved name from released module storage, which can fault in string(). Hold key->sem for reading across kasprintf(). The collector then cannot retype the key or complete retirement until both formatting passes have finished. If retirement wins the lock first, formatting uses the core key_type_dead name instead. Release the semaphore immediately after kasprintf(), including on allocation failure, before copying to userspace. Oops report as below: BUG: unable to handle page fault for address: fffffbfff8054794 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page RIP: 0010:string+0x23f/0x470 Call Trace: vsnprintf+0x330/0x1110

Metrics

CVSS 3.1

7/10

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.11%

1.5th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= aa9d4437893f7e015ce5b6d6c443a9ba92c8a2e7, < 19c4de819e52b7f606468fbfe4fcef4e812e2777; >= aa9d4437893f7e015ce5b6d6c443a9ba92c8a2e7, < a49e6c9a1a5b3457c946a8efb616ce13b4ca8194; >= aa9d4437893f7e015ce5b6d6c443a9ba92c8a2e7, < 916667df7695366f23cfaf365b5840b228cc4b2e; >= aa9d4437893f7e015ce5b6d6c443a9ba92c8a2e7, < dddd3a1ab7d12ee163477918ff6eb943361db4fe; >= aa9d4437893f7e015ce5b6d6c443a9ba92c8a2e7, < 3c3cfd9e262afc9558c38f8cec57f09d10988546; >= aa9d4437893f7e015ce5b6d6c443a9ba92c8a2e7, < 6b613747f7ea309ada5b8d05b55398c338f7a968; >= aa9d4437893f7e015ce5b6d6c443a9ba92c8a2e7, < dea367df18e3a4faac393e3a4e818ee03af89b19; >= aa9d4437893f7e015ce5b6d6c443a9ba92c8a2e7, < 0461bc8f91116aae4a020e15f4e1c1fd535ab35e; >= aa9d4437893f7e015ce5b6d6c443a9ba92c8a2e7, < fced7238b7e80cf8aa688d5af976e4aa6e33c329
Linux	Linux	3.18

References

Timeline

Published: Nov 2, 2026
Last Modified: Nov 3, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-99224?

In the Linux kernel, the following vulnerability has been resolved: keys: Protect the type name while describing a key keyctl_describe_key() must keep the key type's name alive until kasprintf() has consumed it. The retained key reference keeps the key and its description alive, but does not pin the module providing its type. The name is passed to kasprintf() without holding key->sem. kvasprintf() uses the saved name pointer in two formatting passes, with a GFP_KERNEL allocation between them. With AF_RXRPC=m, a task that passes View permission before type retirement can overlap a privileged module unload in this order: 1. KEYCTL_DESCRIBE looks up the key, saves key->type->name in the kasprintf() arguments and completes the first formatting pass. 2. While the formatter is delayed before its second pass, af_rxrpc_exit() calls unregister_key_type(), which removes the type from the registry and waits for key_gc_keytype(). 3. The collector takes key->sem for writing, retypes the retained key to key_type_dead and completes retirement. Unregistration and module exit return, allowing free_module() to release the type and name. 4. The formatter resumes its second pass and reads the saved name from released module storage, which can fault in string(). Hold key->sem for reading across kasprintf(). The collector then cannot retype the key or complete retirement until both formatting passes have finished. If retirement wins the lock first, formatting uses the core key_type_dead name instead. Release the semaphore immediately after kasprintf(), including on allocation failure, before copying to userspace. Oops report as below: BUG: unable to handle page fault for address: fffffbfff8054794 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page RIP: 0010:string+0x23f/0x470 Call Trace: vsnprintf+0x330/0x1110

How severe is CVE-2026-99224?

CVE-2026-99224 has a CVSS score of 7/10 (HIGH severity). The EPSS model estimates a 0.11% probability of exploitation in the next 30 days.

How do I fix CVE-2026-99224?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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