CVE-2022-49931

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

IB/hfi1: Correctly move list in sc_disable()

Commit 13bac861952a ("IB/hfi1: Fix abba locking issue with sc_disable()") incorrectly tries to move a list from one list head to another. The result is a kernel crash.

The crash is triggered when a link goes down and there are waiters for a send to complete. The following signature is seen:

BUG: kernel NULL pointer dereference, address: 0000000000000030 [...] Call Trace: sc_disable+0x1ba/0x240 [hfi1] pio_freeze+0x3d/0x60 [hfi1] handle_freeze+0x27/0x1b0 [hfi1] process_one_work+0x1b0/0x380 ? process_one_work+0x380/0x380 worker_thread+0x30/0x360 ? process_one_work+0x380/0x380 kthread+0xd7/0x100 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30

The fix is to use the correct call to move the list.

A bug in sc_disable() of the hfi1 InfiniBand driver could lead to a kernel NULL pointer dereference when the link goes down with pending waiters. The issue is caused by incorrect list manipulation, resulting in a crash due to dereferencing a NULL list pointer. Only privileged users can trigger this by manipulating InfiniBand links or contexts.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.