Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
arm64: ptrace: Keep ‘orig_x0’ in-sync with x0 on syscall entry
Commit e057b9477232 (“arm64: syscall: Ensure saved x0 is kept in-sync with tracer updates”) attempted to resolve a long-standing issue with syscall entry tracing, where a tracer is able to manipulate the first syscall argument without being subjected to seccomp or audit checking.
Unfortunately, that fix was incomplete [1], as it failed to update ‘orig_x0’ between a tracer updating x0 during a seccomp ptrace exit (SECCOMP_RET_TRACE) and the seccomp filter being re-evaluated.
Rather than add hooks to the core seccomp code, instead move the synchronisation code into the ptrace GPR and syscall setting code so that ‘orig_x0’ is kept up to date with x0 whenever we’re stopped on the syscall entry path.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.10.259 (+12 more)