On Thu, Nov 21, 2019, at 1:09 PM, Daniel Xu wrote:
> /proc/<pid>/io is currently only owner readable. This forces monitoring
> programs (such as atop) to run with elevated permissions to collect disk
> stats. Changing this file to world readable can add a measure of safety to
> userspace.
>
> Signed-off-by: Daniel Xu <dxu@xxxxxxxxx>
> ---
> fs/proc/base.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/proc/base.c b/fs/proc/base.c
> index ebea9501afb8..1d1c1d680e16 100644
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -3076,7 +3076,7 @@ static const struct pid_entry tgid_base_stuff[] = {
> REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
> #endif
> #ifdef CONFIG_TASK_IO_ACCOUNTING
> - ONE("io", S_IRUSR, proc_tgid_io_accounting),
> + ONE("io", S_IRUGO, proc_tgid_io_accounting),
> #endif
> #ifdef CONFIG_USER_NS
> REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
> @@ -3473,7 +3473,7 @@ static const struct pid_entry tid_base_stuff[] = {
> REG("fail-nth", 0644, proc_fail_nth_operations),
> #endif
> #ifdef CONFIG_TASK_IO_ACCOUNTING
> - ONE("io", S_IRUSR, proc_tid_io_accounting),
> + ONE("io", S_IRUGO, proc_tid_io_accounting),
> #endif
> #ifdef CONFIG_USER_NS
> REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
> --
> 2.21.0
>
>
Nevermind, abandoning. Just found 1d1221f375c94ef961b ("proc: restrict access to /proc/PID/io").
