eventfs: Use children field for rcu head and add memory barriers
Get instant alerts when new vulnerabilities affect Linux - before attackers find them.
In the Linux kernel, the following vulnerability has been resolved: eventfs: Use children field for rcu head and add memory barriers When an eventfs inode is freed, it sets ei->is_freed and then uses its ei->list to add it to the srcu link list as the list field is a union with the rcu list head. As the ei->list is used to iterate over an SRCU protected list without taking the eventfs_mutex, there's nothing stopping the iteration over that list to see the ei->rcu instead of the ei->list and it will read a corrupt target. To fix this, change the union of the rcu list head with the children list. On freeing the eventfs inode, set the is_free and execute a smp_wmb() before adding the eventfs inode to the SRCU list. On iteration of the ei->children list, at the start, execute a smp_rmb() and then read the is_freed of the ei to see if the children list is still valid. If is_freed is set, then the ei_child read is not valid and the loop should exit immediately.
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.
Get alerted
Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.