Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
net/xen-netback: prevent UAF in xenvif_flush_hash()
During the list_for_each_entry_rcu iteration call of xenvif_flush_hash, kfree_rcu does not exist inside the rcu read critical section, so if kfree_rcu is called when the rcu grace period ends during the iteration, UAF occurs when accessing head->next after the entry becomes free.
Therefore, to solve this, you need to change it to list_for_each_entry_safe.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 6 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 6 ELS , CloudLinux 7 ELS , Oracle Linux 6 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS
- Affected packages:
- kernel-uek @ 5.4.17 (+15 more)
In the Linux kernel, the following vulnerability has been resolved:
net/xen-netback: prevent UAF in xenvif_flush_hash()
During the list_for_each_entry_rcu iteration call of xenvif_flush_hash, kfree_rcu does not exist inside the rcu read critical section, so if kfree_rcu is called when the rcu grace period ends during the iteration, UAF occurs when accessing head->next after the entry becomes free.
Therefore, to solve this, you need to change it to list_for_each_entry_safe.