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
rmmod bonding
bonding_exit()
bond_destroy_debugfs()
debugfs_remove_recursive(bonding_debug_root);

CPU2
echo -bond0 > /sys/class/net/bonding_masters
bond_uninit()
bond_debug_unregister()
if (!bonding_debug_root)

CPU1
bonding_debug_root = NULL;

So do NOT revert the bad commit (since the removed checks were racy
anyway), and instead change the order of actions taken during module
removal. The same oops can also happen if there is an error during
module init, so apply the same fix there.
History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-05-04T09:16:14.106Z

Reserved: 2024-06-24T13:54:11.074Z

Link: CVE-2024-39296

cve-icon Vulnrichment

Updated: 2024-08-02T04:19:20.715Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2024-06-25T15:15:14.070

Modified: 2024-11-21T09:27:24.520

Link: CVE-2024-39296

cve-icon Redhat

Severity : Low

Publid Date: 2024-06-25T00:00:00Z

Links: CVE-2024-39296 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-07-12T22:31:04Z