Re: [PATCH] mini-os: Avoid segfaults in tc{g,s}etattr

[Wei Liu <wl@xxxxxxx>]

On Mon, Apr 27, 2020 at 09:54:29AM +0200, Samuel Thibault wrote:
> Jason Andryuk, le dim. 26 avril 2020 23:40:19 -0400, a ecrit:
> > Commit c96c22f1d94 "mini-os: minimal implementations of some termios
> > functions" introduced implementations of tcgetattr and tcsetattr.
> > However, they do not check if files[fildes].cons.dev is non-NULL before
> > dereferencing.  This is not a problem for FDs allocated through
> > alloc_fd, but the files array pre-allocates FDs 0-2 for stdio.  Those
> > entries have a NULL .dev, so tc{g,s}etattr on them segfault.
> > 
> > ioemu-stubdom segfaults when term_init() calls tcgetattr on FD 0.
> > 
> > Restore tcgetattr and tcsetattr behavior when .dev is NULL equivalent to
> > unsupported_function as it was before c96c22f1d94.
> > 
> > Signed-off-by: Jason Andryuk <jandryuk@xxxxxxxxx>
> 
> Reviewed-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>
> 
> Thanks!

Applied. Thanks.