Re: [PATCH v3] 9pfs: prevent opening special files (CVE-2023-2861)

[Michael Tokarev]

07.06.2023 17:50, Greg Kurz wrote:
> On Wed, 7 Jun 2023 15:50:01 +0200
..
> > +static inline int check_is_regular_file_or_dir(int fd)
> > +{
> > +    struct stat stbuf;
> > +
> > +    if (qemu_fstat(fd, &stbuf) < 0) {
> > +        close_preserve_errno(fd);
>
> Maybe worth to mention somewhere that this function not only
> checks but also closes the fd if it doesn't point to a regular
> file or directory. Or maybe change the name, e.g.
> filter_out_special_files() ?

I realized this after sent initial comment, - my suggestion for
the name was awful. It is either check_is_regular() and close
after it failed, or it is ensure_regular_or_close().. But I
didn't sent a correction, hoping it's easy to spot the awful
suggestion.. :)

I don't like it when such a simple thing, especially when
reviewed without good care like in my case, generates so
much ping-pong.. :(

> Anyway the fix is fine enough to address the CVE.

Yeah.

/mjt