CVE-2022-48653: 
Linux Kernel vulnerability analysis and mitigation

In the Linux kernel's ICE network driver, a vulnerability was discovered where auxiliary (aux) devices were being unplugged twice during a peer-initiated reset. The issue occurs in the IDC callback when aux drivers request a reset, where the function to unplug aux devices is called both in the callback and in the ice_prepare_for_reset function. This double call results in a "scheduling while atomic" bug. The vulnerability was assigned CVE-2022-48653 and was discovered in early 2024 (NVD, Red Hat).

The vulnerability manifests when the aux drivers request a reset through the IDC callback. The ice_unplug_aux_dev function is called twice: once in the callback and again in the ice_prepare_for_reset function. This redundant call sequence triggers a kernel "scheduling while atomic" bug, which occurs when trying to schedule operations while in an atomic context. The issue was traced to the ice_schedule_reset function where the unnecessary additional call to ice_unplug_aux_dev was identified (Kernel Commit).

When triggered, this vulnerability causes a kernel bug that can lead to system instability or crashes. The issue specifically affects systems using the Intel ICE network driver with auxiliary devices. The bug manifests as a "scheduling while atomic" error, which can disrupt normal system operations and potentially affect network connectivity (Red Hat).

The vulnerability is triggered during normal system operation when a peer-initiated reset occurs in conjunction with auxiliary device operations. It requires no special privileges to trigger, as it occurs during standard driver operations. The issue has been observed in production environments, particularly when handling network device resets (Kernel Commit).

The issue has been resolved by removing the redundant call to ice_unplug_aux_dev from the ice_schedule_reset function. The correct place to unplug the aux devices is in the prepare_for_reset function, which is the common place for all reset flows and has built-in protection against double calls. Users should update to a patched version of the Linux kernel that includes this fix (Kernel Commit).