Skip to content
Commit 7e27e8d6 authored by Junwei Hu's avatar Junwei Hu Committed by David S. Miller
Browse files

tipc: switch order of device registration to fix a crash



When tipc is loaded while many processes try to create a TIPC socket,
a crash occurs:
 PANIC: Unable to handle kernel paging request at virtual
 address "dfff20000000021d"
 pc : tipc_sk_create+0x374/0x1180 [tipc]
 lr : tipc_sk_create+0x374/0x1180 [tipc]
   Exception class = DABT (current EL), IL = 32 bits
 Call trace:
  tipc_sk_create+0x374/0x1180 [tipc]
  __sock_create+0x1cc/0x408
  __sys_socket+0xec/0x1f0
  __arm64_sys_socket+0x74/0xa8
 ...

This is due to race between sock_create and unfinished
register_pernet_device. tipc_sk_insert tries to do
"net_generic(net, tipc_net_id)".
but tipc_net_id is not initialized yet.

So switch the order of the two to close the race.

This can be reproduced with multiple processes doing socket(AF_TIPC, ...)
and one process doing module removal.

Fixes: a62fbcce ("tipc: make subscriber server support net namespace")
Signed-off-by: default avatarJunwei Hu <hujunwei4@huawei.com>
Reported-by: default avatarWang Wang <wangwang2@huawei.com>
Reviewed-by: default avatarXiaogang Wang <wangxiaogang3@huawei.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 61fb0d01
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment