Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
apparmor: replace recursive profile removal with iterative approach
The profile removal code uses recursion when removing nested profiles, which can lead to kernel stack exhaustion and system crashes.
Reproducer: $ pf=‘a’; for ((i=0; i<1024; i++)); do echo -e “profile $pf { \n }” | apparmor_parser -K -a; pf="$pf//x"; done $ echo -n a > /sys/kernel/security/apparmor/.remove
Replace the recursive __aa_profile_list_release() approach with an iterative approach in __remove_profile(). The function repeatedly finds and removes leaf profiles until the entire subtree is removed, maintaining the same removal semantic without recursion.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux-hwe @ 4.15.0 (+13 more)
In the Linux kernel, the following vulnerability has been resolved:
apparmor: replace recursive profile removal with iterative approach
The profile removal code uses recursion when removing nested profiles, which can lead to kernel stack exhaustion and system crashes.
Reproducer: $ pf=‘a’; for ((i=0; i<1024; i++)); do echo -e “profile $pf { \n }” | apparmor_parser -K -a; pf="$pf//x"; done $ echo -n a > /sys/kernel/security/apparmor/.remove
Replace the recursive __aa_profile_list_release() approach with an iterative approach in __remove_profile(). The function repeatedly finds and removes leaf profiles until the entire subtree is removed, maintaining the same removal semantic without recursion.