On Mon, Oct 29, 2018 at 10:41:22AM -0400, Olga Kornievskaia wrote: > On Sat, Oct 27, 2018 at 5:27 AM Dave Chinner <david@xxxxxxxxxxxxx> wrote: > > > > On Fri, Oct 26, 2018 at 04:10:48PM -0400, Olga Kornievskaia wrote: > > > From: Olga Kornievskaia <kolga@xxxxxxxxxx> > > > > > > Input source offset can't be beyond the end of the file. > > > > > > Signed-off-by: Olga Kornievskaia <kolga@xxxxxxxxxx> > > > --- > > > fs/read_write.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/fs/read_write.c b/fs/read_write.c > > > index fb4ffca..b3b304e 100644 > > > --- a/fs/read_write.c > > > +++ b/fs/read_write.c > > > @@ -1594,6 +1594,9 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, > > > } > > > } > > > > > > + if (pos_in >= i_size_read(inode_in)) > > > + return -EINVAL; > > > + > > > > vfs_copy_file_range seems ot be missing a wide range of checks. > > rlimit, s_maxbytes, LFS file sizes, etc. This is a write, so all the > > checks in generic_write_checks() apply, right? And the same security > > issues like stripping setuid bits, etc? And we need to touch > > atime on the source file, too? > > Yes sound like needed checks. > > > We've just merged 5 or so patches in 4.19-rc8 and we're ready to > > merge another ~30 patch series to fix all the stuff missing from the > > clone/dedupe file range operations that make them safe and robust. > > It seems like copy_file_range is all the checks it needs, too? > > Are you proposing to not do this check now in favor of the proper work > that will do all of those checks you listed above? No, I'm saying that if you're adding one check, there's a whole heap of checks that still need to be added, *especially* if this is going to fall back to page cache copy between superblocks that may have different limits and constraints. There's security issues in this API. They need to be fixed before we allow it to do more and potentially expose more problems due to it's wider capability. > I can not volunteer > to provide this comprehensive check. Why not? Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx
