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.
Metrics
Affected Vendors & Products
References
History
No history.
MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2024-06-25T14:22:40.218Z
Updated: 2024-11-05T09:31:40.637Z
Reserved: 2024-06-24T13:54:11.074Z
Link: CVE-2024-39296
Vulnrichment
Updated: 2024-06-25T20:46:50.961Z
NVD
Status : Awaiting Analysis
Published: 2024-06-25T15:15:14.070
Modified: 2024-11-21T09:27:24.520
Link: CVE-2024-39296
Redhat