CVE-2023-53591

/// Technical description

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

net/mlx5e: Fix deadlock in tc route query code

Cited commit causes ABBA deadlock[0] when peer flows are created while

holding the devcom rw semaphore. Due to peer flows offload implementation

the lock is taken much higher up the call chain and there is no obvious way

to easily fix the deadlock. Instead, since tc route query code needs the

peer eswitch structure only to perform a lookup in xarray and doesn't

perform any sleeping operations with it, refactor the code for lockless

execution in following ways:

- RCUify the devcom 'data' pointer. When resetting the pointer

synchronously wait for RCU grace period before returning. This is fine

since devcom is currently only used for synchronization of

pairing/unpairing of eswitches which is rare and already expensive as-is.

- Wrap all usages of 'paired' boolean in {READ|WRITE}_ONCE(). The flag has

already been used in some unlocked contexts without proper

annotations (e.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References