CVE-2024-26934

In the Linux kernel, the following vulnerability has been resolved:

USB: core: Fix deadlock in usb_deauthorize_interface()

Among the attribute file callback routines in drivers/usb/core/sysfs.c, the interface_authorized_store() function is the only one which acquires a device lock on an ancestor device: It calls usb_deauthorize_interface(), which locks the interfaces parent USB device.

The will lead to deadlock if another process already owns that lock and tries to remove the interface, whether through a configuration change or because the device has been disconnected. As part of the removal procedure, device_del() waits for all ongoing sysfs attribute callbacks to complete. But usb_deauthorize_interface() cant complete until the device lock has been released, and the lock wont be released until the removal has finished.

The mechanism provided by sysfs to prevent this kind of deadlock is to use the sysfs_break_active_protection() function, which tells sysfs not to wait for the attribute callback.

Reported-and-tested by: Yue Sun samsun1006219@gmail.com Reported by: xingwei lee xrivendell7@gmail.com

Weakness

The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

Affected Software

Extended Description

Locking is a type of synchronization behavior that ensures that multiple independently-operating processes or threads do not interfere with each other when accessing the same resource. All processes/threads are expected to follow the same steps for locking. If these steps are not followed precisely - or if no locking is done at all - then another process/thread could modify the shared resource in a way that is not visible or predictable to the original process. This can lead to data or memory corruption, denial of service, etc.

Potential Mitigations

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/25.html
• https://cwe.mitre.org/data/definitions/26.html
• https://cwe.mitre.org/data/definitions/27.html

References

• https://git.kernel.org/stable/c/07acf979da33c721357ff27129edf74c23c036c6
• https://git.kernel.org/stable/c/122a06f1068bf5e39089863f4f60b1f5d4273384
• https://git.kernel.org/stable/c/12d6a5681a0a5cecc2af7860f0a1613fa7c6e947
• https://git.kernel.org/stable/c/1b175bc579f46520b11ecda443bcd2ee4904f66a
• https://git.kernel.org/stable/c/80ba43e9f799cbdd83842fc27db667289b3150f5
• https://git.kernel.org/stable/c/8cbdd324b41528994027128207fae8100dff094f
• https://git.kernel.org/stable/c/ab062fa3dc69aea88fe62162c5881ba14b50ecc5
• https://git.kernel.org/stable/c/dbdf66250d2d33e8b27352fcb901de79f3521057
• https://git.kernel.org/stable/c/e451709573f8be904a8a72d0775bf114d7c291d9
• https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html
• https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html