On Tue 30-05-23 13:21:47, Jan Kara wrote: > On Fri 26-05-23 11:45:57, Roberto Sassu wrote: > > On Wed, 2023-05-24 at 17:57 -0400, Paul Moore wrote: > > > On Wed, May 24, 2023 at 11:50 AM Roberto Sassu > > > <roberto.sassu@xxxxxxxxxxxxxxx> wrote: > > > > On Wed, 2023-05-24 at 11:11 -0400, Paul Moore wrote: > > > > > On Wed, May 24, 2023 at 5:59 AM syzbot > > > > > <syzbot+0a684c061589dcc30e51@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > > > > > syzbot has bisected this issue to: > > > > > > > > > > > > commit d82dcd9e21b77d338dc4875f3d4111f0db314a7c > > > > > > Author: Roberto Sassu <roberto.sassu@xxxxxxxxxx> > > > > > > Date: Fri Mar 31 12:32:18 2023 +0000 > > > > > > > > > > > > reiserfs: Add security prefix to xattr name in reiserfs_security_write() > > > > > > > > > > > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11c39639280000 > > > > > > start commit: 421ca22e3138 Merge tag 'nfs-for-6.4-2' of git://git.linux-.. > > > > > > git tree: upstream > > > > > > final oops: https://syzkaller.appspot.com/x/report.txt?x=13c39639280000 > > > > > > console output: https://syzkaller.appspot.com/x/log.txt?x=15c39639280000 > > > > > > kernel config: https://syzkaller.appspot.com/x/.config?x=7d8067683055e3f5 > > > > > > dashboard link: https://syzkaller.appspot.com/bug?extid=0a684c061589dcc30e51 > > > > > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14312791280000 > > > > > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12da8605280000 > > > > > > > > > > > > Reported-by: syzbot+0a684c061589dcc30e51@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > > > Fixes: d82dcd9e21b7 ("reiserfs: Add security prefix to xattr name in reiserfs_security_write()") > > > > > > > > > > > > For information about bisection process see: https://goo.gl/tpsmEJ#bisection > > > > > > > > > > Roberto, I think we need to resolve this somehow. As I mentioned > > > > > earlier, I don't believe this to be a fault in your patch, rather that > > > > > patch simply triggered a situation that had not been present before, > > > > > likely because the reiserfs code always failed when writing LSM > > > > > xattrs. Regardless, we still need to fix the deadlocks that sysbot > > > > > has been reporting. > > > > > > > > Hi Paul > > > > > > > > ok, I will try. > > > > > > Thanks Roberto. If it gets to be too challenging, let us know and we > > > can look into safely disabling the LSM xattrs for reiserfs, I'll be > > > shocked if anyone is successfully using LSM xattrs on reiserfs. > > > > Ok, at least I know what happens... > > > > + Jan, Jeff > > > > I'm focusing on this reproducer, which works 100% of the times: > > > > https://syzkaller.appspot.com/text?tag=ReproSyz&x=163079f9280000 > > Well, the commit d82dcd9e21b ("reiserfs: Add security prefix to xattr name > in reiserfs_security_write()") looks obviously broken to me. It does: > > char xattr_name[XATTR_NAME_MAX + 1] = XATTR_SECURITY_PREFIX; > > Which is not how we can initialize strings in C... ;) I'm growing old or what but indeed string assignment in initializers in C works fine. It is only the assignment in code that would be problematic. I'm sorry for the noise. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
