sysctl: setting key "net.core.bpf_jit_enable": Invalid argument

[Paul Menzel]

Dear Linux folks,


Related to * [CVE-2021-29154] Linux kernel incorrect computation of 
branch displacements in BPF JIT compiler can be abused to execute 
arbitrary code in Kernel mode* [1], on the POWER8 system IBM S822LC with 
self-built Linux 5.12.0-rc5+, I am unable to disable `bpf_jit_enable`.

     $ /sbin/sysctl net.core.bpf_jit_enable
     net.core.bpf_jit_enable = 1
     $ sudo /sbin/sysctl -w net.core.bpf_jit_enable=0
     sysctl: setting key "net.core.bpf_jit_enable": Invalid argument

It works on an x86 with Debian sid/unstable and Linux 5.10.26-1.


Kind regards,

Paul


[1]: https://seclists.org/oss-sec/2021/q2/12