CVE-2024-43862

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

net: wan: fsl_qmc_hdlc: Convert carrier_lock spinlock to a mutex

The carrier_lock spinlock protects the carrier detection. While it is held, framer_get_status() is called which in turn takes a mutex. This is not correct and can lead to a deadlock.

A run with PROVE_LOCKING enabled detected the issue: [ BUG: Invalid wait context ] ... c204ddbc (&framer->mutex){+.+.}-{3:3}, at: framer_get_status+0x40/0x78 other info that might help us debug this: context-{4:4} 2 locks held by ifconfig/146: #0: c0926a38 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x12c/0x664 #1: c2006a40 (&qmc_hdlc->carrier_lock){....}-{2:2}, at: qmc_hdlc_framer_set_carrier+0x30/0x98

Avoid the spinlock usage and convert carrier_lock to a mutex.

Following issue marked as moderate with "not affected or will not fix" for Red Hat Enterprise Linux, as it is not vulnerable to this CVE. This is because the CVE does not impact the versions or configurations of the Linux kernel used in Red Hat's distributions.

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.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.