bug#76648: Crash trying to parse nilfs2 superblock

On Fri, Feb 28, 2025 at 03:21:00PM +0000, Butenko, Anton via Bug reports for the GNU Parted disk partition editor wrote:
> Hello,
> 
> I was checking how good is fix of
> 
> https://debbugs.gnu.org/cgi/bugreport.cgi?bug=34392
> “Avoid sigsegv in case 2nd nilfs2 superblock magic accidently found.”
> 
> In systemd, libblkid and parted and found a slight possibility of crash in parted regarding to the changes in the referred bug.
> The parted fix includes a chance to crash in case of nilfs2 superblock having correct magic, but corrupted “bytes” field (value in range from 12 to 20).
> 
> I’ve modified the code to avoid the sigsegv and align implementation with the libblkid implementation:
> https://github.com/util-linux/util-linux/commit/ac681a310c32319423297544833932f4d689a7a2
> And modified t4301-nilfs2-badsb2.sh test code to trigger this case as well as the previously reported one.
> 
> I've attached a patch with my modifications. Can you, please, look at it?

Sorry it took so long to look at this, it looks good to me. I'm posting
it to the parted-devel list and if there are no objections I'll push it
by Friday.

Thanks,

Brian

-- 
Brian C. Lane (PST8PDT) - weldr.io - lorax - parted - pykickstart