Re: [syzbot] [serial?] KASAN: use-after-free Read in gsm_cleanup_mux

[syzbot]

syzbot suspects this issue was fixed by commit:

commit 3c4f8333b582487a2d1e02171f1465531cde53e3
Author: Yi Yang <yiyang13@xxxxxxxxxx>
Date:   Fri Aug 11 03:11:21 2023 +0000

    tty: n_gsm: fix the UAF caused by race condition in gsm_cleanup_mux

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=121e6a92680000
start commit:   a4412fdd49dc error-injection: Add prompt for function erro..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=cc4b2e0a8e8a8366
dashboard link: https://syzkaller.appspot.com/bug?extid=893c55305230e719a203
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12b1ca83880000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1023c5e3880000

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

#syz fix: tty: n_gsm: fix the UAF caused by race condition in gsm_cleanup_mux

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