CVE-2024-46791

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

can: mcp251x: fix deadlock if an interrupt occurs during mcp251x_open

The mcp251x_hw_wake() function is called with the mpc_lock mutex held and disables the interrupt handler so that no interrupts can be processed while waking the device. If an interrupt has already occurred then waiting for the interrupt handler to complete will deadlock because it will be trying to acquire the same mutex.

CPU0 CPU1

mcp251x_open() mutex_lock(&priv->mcp_lock) request_threaded_irq() mcp251x_can_ist() mutex_lock(&priv->mcp_lock) mcp251x_hw_wake() disable_irq() <– deadlock

Use disable_irq_nosync() instead because the interrupt handler does everything while holding the mutex so it doesnt matter if its still running.

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/3a49b6b1caf5cefc05264d29079d52c99cb188e0
• https://git.kernel.org/stable/c/513c8fc189b52f7922e36bdca58997482b198f0e
• https://git.kernel.org/stable/c/7dd9c26bd6cf679bcfdef01a8659791aa6487a29
• https://git.kernel.org/stable/c/8fecde9c3f9a4b97b68bb97c9f47e5b662586ba7
• https://git.kernel.org/stable/c/e554113a1cd2a9cfc6c7af7bdea2141c5757e188
• https://git.kernel.org/stable/c/f7ab9e14b23a3eac6714bdc4dba244d8aa1ef646
• https://lists.debian.org/debian-lts-announce/2024/10/msg00003.html
• https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html