Re: INFO: trying to register non-static key in rhashtable_walk_enter

On Sat, May 18, 2019 at 2:09 PM Willem de Bruijn
[off-list ref] wrote:

On Sat, May 18, 2019 at 3:34 AM syzbot
[off-list ref] wrote:

quoted

Hello,

syzbot found the following crash on:

HEAD commit:    510e2ced ipv6: fix src addr routing with the exception table
git tree:       net
console output: https://syzkaller.appspot.com/x/log.txt?x=15b7e608a00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=82f0809e8f0a8c87
dashboard link: https://syzkaller.appspot.com/bug?extid=1e8114b61079bfe9cbc5
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+1e8114b61079bfe9cbc5@syzkaller.appspotmail.com

INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.

All these five rhashtable_walk_enter probably have the same root cause.

Bisected to commit 7e27e8d6130c (" tipc: switch order of device
registration to fix a crash"). Reverting that fixes it.

Before the commit, tipc_init succeeds. After the commit it fails at
register_pernet_subsys(&tipc_net_ops) due to error in

  tipc_init_net
    tipc_topsrv_start
      tipc_topsrv_create_listener
        sock_create_kern

On a related note, in tipc_topsrv_start srv is also not freed on later
error paths.

and tipc_topsrv_stop is not called in tipc_init_net on later error paths.