CVE-2024-47696

/// Technical description

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

RDMA/iwcm: Fix WARNING:at_kernel/workqueue.c:#check_flush_dependency

In the commit aee2424246f9 ("RDMA/iwcm: Fix a use-after-free related to

destroying CM IDs"), the function flush_workqueue is invoked to flush the

work queue iwcm_wq.

But at that time, the work queue iwcm_wq was created via the function

alloc_ordered_workqueue without the flag WQ_MEM_RECLAIM.

Because the current process is trying to flush the whole iwcm_wq, if

iwcm_wq doesn't have the flag WQ_MEM_RECLAIM, verify that the current

process is not reclaiming memory or running on a workqueue which doesn't

have the flag WQ_MEM_RECLAIM as that can break forward-progress guarantee

leading to a deadlock.

The call trace is as below:

[ 125.350876][ T1430] Call Trace:

[ 125.356281][ T1430] <TASK>

[ 125.361285][ T1430] ? __warn (kernel/panic.c:693)

[ 125.367640][ T1430] ? check_flush_dependency (kernel/workqueue.c:3706 (discriminator 9))

[ 125.375689][ T14

/// 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