Re: [syzbot] [mm?] possible deadlock in __mmap_lock_do_trace_released

[Tetsuo Handa]

The local lock itself will be removed by

mm: mmap_lock: replace get_memcg_path_buf() with on-stack buffer

but is there possibility that this bpf program forms an infinite
recursion (kernel stack overflow) bug?

On 2024/07/03 3:54, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    a12978712d90 selftests/bpf: Move ARRAY_SIZE to bpf_misc.h
> git tree:       bpf-next
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=130457fa980000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=736daf12bd72e034
> dashboard link: https://syzkaller.appspot.com/bug?extid=16b6ab88e66b34d09014
> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=125718be980000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14528876980000