On 3/12/24, Jan Kara <jack@xxxxxxx> wrote: > On Mon 11-03-24 20:01:14, Mateusz Guzik wrote: >> On 3/11/24, Jan Kara <jack@xxxxxxx> wrote: >> > On Mon 11-03-24 11:04:04, syzbot wrote: >> >> syzbot suspects this issue was fixed by commit: >> >> >> >> commit 6f861765464f43a71462d52026fbddfc858239a5 >> >> Author: Jan Kara <jack@xxxxxxx> >> >> Date: Wed Nov 1 17:43:10 2023 +0000 >> >> >> >> fs: Block writes to mounted block devices >> >> >> >> bisection log: >> >> https://syzkaller.appspot.com/x/bisect.txt?x=17e3f58e180000 >> >> start commit: eb3479bc23fa Merge tag 'kbuild-fixes-v6.7' of >> >> git://git.ke.. >> >> git tree: upstream >> >> kernel config: >> >> https://syzkaller.appspot.com/x/.config?x=bdf178b2f20f99b0 >> >> dashboard link: >> >> https://syzkaller.appspot.com/bug?extid=6ec38f7a8db3b3fb1002 >> >> syz repro: >> >> https://syzkaller.appspot.com/x/repro.syz?x=15073fd4e80000 >> >> C reproducer: >> >> https://syzkaller.appspot.com/x/repro.c?x=17b20b8f680000 >> >> >> >> If the result looks correct, please mark the issue as fixed by >> >> replying >> >> with: >> > >> > #syz fix: fs: Block writes to mounted block devices >> > >> >> I don't think that's correct. >> >> The bug is ntfs instantiating an inode with bogus type (based on an >> intentionally corrupted filesystem), violating the api contract with >> vfs, which in turn results in the warning way later. >> >> It may be someone sorted out ntfs doing this in the meantime, I have >> not checked. >> >> With this in mind I don't believe your patch fixed it, at best it >> happened to neuter the reproducer. > > OK, I didn't dig deep into the bug. I've just seen there are no working > reproducers and given this is ntfs3 which doesn't really have great > maintenance effort put into it, I've opted for closing the bug. If there's > a way to tickle the bug without writing to mounted block device, syzbot > should eventually find it and create a new issue... But if you want to look > into this feel free to :) Thanks for sharing the info. > Maybe I'll get around to future-proofing by adding validation before the inode escapes the filesystem code, but I'm definitely NOT patching ntfs. 8-> -- Mateusz Guzik <mjguzik gmail.com>
