Re: [syzbot] KASAN: use-after-free Read in mas_next_nentry

From: syzbot
Date: Wed Jan 25 2023 - 17:04:23 EST


syzbot suspects this issue was fixed by commit:

commit 59f2f4b8a757412fce372f6d0767bdb55da127a8
Author: Liam Howlett <liam.howlett@xxxxxxxxxx>
Date: Mon Nov 7 20:11:42 2022 +0000

fs/userfaultfd: Fix maple tree iterator in userfaultfd_unregister()

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=129e8afe480000
start commit: b229b6ca5abb Merge tag 'perf-tools-fixes-for-v6.1-2022-10-..
git tree: upstream
kernel config: https://syzkaller.appspot.com/x/.config?x=a66c6c673fb555e8
dashboard link: https://syzkaller.appspot.com/bug?extid=7170d66493145b71afd4
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11bfb2a9880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10b1d319880000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: fs/userfaultfd: Fix maple tree iterator in userfaultfd_unregister()

For information about bisection process see: https://goo.gl/tpsmEJ#bisection