Sanity-check the XFS superblock for wellformedness at the mount handler.
This forces pygrub to abort parsing a potentially malformed filesystem and
ensures the invariants assumed throughout the rest of the code hold.
Also, derive parameters from previously sanitized parameters where possible
(rather than reading them off the superblock)
The code doesn't try to avoid overflowing the end of the disk, because
that's an unlikely and benign error. Parameters used in calculations of
xfs_daddr_t (like the root inode index) aren't in critical need of being
sanitized.
The sanitization of agblklog is basically checking that no obvious
overflows happen on agblklog, and then ensuring agblocks is contained in
the range (2^(sb_agblklog-1), 2^sb_agblklog].
This is part of XSA-443 / CVE-2023-34325
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
As recommended in http://www.gnu.org/licenses/gpl-howto.en.html.
This is the result of:
$ git grep -El Mass\|Temple\|Franklin | xargs ./fsf.pl
Where fsf.pl is:
#!/usr/bin/perl -w -pi.bak -0777
my $repl = 'If not, see <http://www.gnu.org/licenses/>.';
my $br = qr/(?:\s*\n\s*(?:[\*\#]|\/\/|\.\\" )?\s*|\s+)/;
my $inwt = qr/[Ii]f${br}not,${br}write${br}(?:to${br})?the${br}Free${br}Software${br}Foundation,(?:${br}Inc\.,)?/;
my $mass = qr/675${br}Mass${br}Ave,?${br}Cambridge,?${br}MA${br}02139,?${br}USA,?\.?/;
my $franklin = qr/51${br}Franklin${br}St(?:reet)?(?:,${br}| - )Fifth${br}Floor,?${br}Boston,?${br}MA,?${br}02110-1301,?${br}USA,?\.?/;
my $temple = qr/59${br}Temple${br}Place(?:,${br}| - )Suite${br}330,?${br}Boston,?${br}MA,?${br}021110?-1307,?${br}USA,?\.?/;
s|$inwt$br$mass|$repl|m;
s|$inwt$br$franklin|$repl|m;
s|$inwt$br$temple|$repl|m;
The only remaining mentions of these addresses are in COPYING files which I
haven't touched.
Some of the changed files are imports from elsewhere, however
filtering them out is tricky, I think it is tolerable to have these
files be modified here and then perhaps reverted on the next sync,
since it's only 1-2 lines and obvious what is going on.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Alejandro Vallejo
Ian Campbell
Marco Nenciarini