On Tue, Jun 05, 2018 at 12:47:33PM -0500, Eric W. Biederman wrote: > Sigh, I have found another issue with kernfs_fop_readdir. > > We are not currently protecting file->private_data with the kernfs_mutex > or any other kind of serialization. Which means if two processes are > calling readdir on the same file descriptor we might get unpredictable > behavior. > > It doesn't look too bad and easy enough to fix, but definitely something > to be watchful of.
As discussed off-list - this is not a problem; getdents() et.al. are serialized on per-struct-file basis by fdget_pos() in relevant syscalls, since all directories automatically get FMODE_ATOMIC_POS in ->f_mode.
