From: Junwei Hu <hujunwei4@xxxxxxxxxx>
[ 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: a62fbccecd62 ("tipc: make subscriber server support net namespace")
Signed-off-by: Junwei Hu <hujunwei4@xxxxxxxxxx>
Reported-by: Wang Wang <wangwang2@xxxxxxxxxx>
Reviewed-by: Xiaogang Wang <wangxiaogang3@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/tipc/core.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
--- a/net/tipc/core.c
+++ b/net/tipc/core.c
@@ -125,10 +125,6 @@ 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;
@@ -137,6 +133,10 @@ 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;
@@ -144,12 +144,12 @@ 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();
@@ -161,10 +161,10 @@ 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");
