evie/android_kernel_oneplus_msm8998
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

tipc: switch order of device registration to fix a crash

Browse source 
[ Upstream commit 7e27e8d6130c5e88fac9ddec4249f7f2337fe7f8 ]

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: a62fbccecd ("tipc: make subscriber server support net namespace")
Signed-off-by: Junwei Hu <hujunwei4@huawei.com>
Reported-by: Wang Wang <wangwang2@huawei.com>
Reviewed-by: Xiaogang Wang <wangxiaogang3@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Junwei Hu 2019-05-16 10:51:15 +08:00 • committed by Greg Kroah-Hartman
parent 2ff783f3e0
commit ff69bb4be6
1 changed files with 7 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
net/tipc/core.c
View file

@ -126,10 +126,6 @@ static int __init tipc_init(void)
if (err)
goto out_netlink_compat;
err = tipc_socket_init();
if (err)
goto out_socket;
err = tipc_register_sysctl();
if (err)
goto out_sysctl;
@ -138,6 +134,10 @@ static int __init tipc_init(void)
if (err)
goto out_pernet;
err = tipc_socket_init();
if (err)
goto out_socket;
err = tipc_bearer_setup();
if (err)
goto out_bearer;
@ -145,12 +145,12 @@ static int __init tipc_init(void)
pr_info("Started in single node mode\n");
return 0;
out_bearer:
tipc_socket_stop();
out_socket:
unregister_pernet_subsys(&tipc_net_ops);
out_pernet:
tipc_unregister_sysctl();
out_sysctl:
tipc_socket_stop();
out_socket:
tipc_netlink_compat_stop();
out_netlink_compat:
tipc_netlink_stop();
@ -162,10 +162,10 @@ out_netlink:
static void __exit tipc_exit(void)
{
tipc_bearer_cleanup();
tipc_socket_stop();
unregister_pernet_subsys(&tipc_net_ops);
tipc_netlink_stop();
tipc_netlink_compat_stop();
tipc_socket_stop();
tipc_unregister_sysctl();
pr_info("Deactivated\n");