Re: [PATCH v2] proc: proc_pid_ns takes super_block as an argument

Alexey Gladkov [off-list ref] writes:

On Mon, May 18, 2020 at 07:08:57AM -0500, Eric W. Biederman wrote:

quoted

Alexey Gladkov [off-list ref] writes:

quoted

The proc_pid_ns() can be used for both inode and dentry. To avoid making
two identical functions, change the argument type of the proc_pid_ns().

Link: https://lore.kernel.org/lkml/c3461e26-1407-2262-c709-dac0df3da2d0@i-love.sakura.ne.jp/ (local)
Reported-by: syzbot+c1af344512918c61362c@syzkaller.appspotmail.com
Signed-off-by: Alexey Gladkov <redacted>

So overall this looks good.

However, the description leaves a little bit to be desired as it does
not describe why it is bad to use dentry->d_sb.  A fixes tag would be
nice if for no other reason than to help anyone who decides to backport
this.

OK. I will add it.

Thank you.  It really helps to have the full description of why in
the commit comments.

quoted

And can you please compile test this?

There is a very silly typo in proc that keeps this from compiling.

I compiled the kernel with this patch and ran the kernel, but accidentally
did not check children_seq_show(). Sorry.

Yes, children_seq_show is behind a sneaky CONFIG option.

Eric