CVE-2024-39296

/// Technical description

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

bonding: fix oops during rmmod

"rmmod bonding" causes an oops ever since commit cc317ea3d927 ("bonding:

remove redundant NULL check in debugfs function"). Here are the relevant

functions being called:

bonding_exit()

bond_destroy_debugfs()

debugfs_remove_recursive(bonding_debug_root);

bonding_debug_root = NULL; <--------- SET TO NULL HERE

bond_netlink_fini()

rtnl_link_unregister()

__rtnl_link_unregister()

unregister_netdevice_many_notify()

bond_uninit()

bond_debug_unregister()

(commit removed check for bonding_debug_root == NULL)

debugfs_remove()

simple_recursive_removal()

down_write() -> OOPS

However, reverting the bad commit does not solve the problem completely

because the original code contains a race that could cause the same

oops, although it was much less likely to be triggered unintentionally:

CPU1

/// 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