On 01.11.22 10:37, Chen Zhongjin wrote:
In smc_init(), register_pernet_subsys(&smc_net_stat_ops) is called
without any error handling.
If it fails, registering of &smc_net_ops won't be reverted.
And if smc_nl_init() fails, &smc_net_stat_ops itself won't be reverted.
This leaves wild ops in subsystem linkedlist and when another module
tries to call register_pernet_operations() it triggers page fault:
BUG: unable to handle page fault for address: fffffbfff81b964c
RIP: 0010:register_pernet_operations+0x1b9/0x5f0
Call Trace:
<TASK>
register_pernet_subsys+0x29/0x40
ebtables_init+0x58/0x1000 [ebtables]
...
Fixes: 194730a9beb5 ("net/smc: Make SMC statistics network namespace aware")
Signed-off-by: Chen Zhongjin <chenzhongjin@xxxxxxxxxx>
It looks good, thank you for the effort!
Reviewed-by: Wenjia Zhang <wenjia@xxxxxxxxxxxxx>
---
net/smc/af_smc.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 3ccbf3c201cd..e12d4fa5aece 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -3380,14 +3380,14 @@ static int __init smc_init(void)
rc = register_pernet_subsys(&smc_net_stat_ops);
if (rc)
- return rc;
+ goto out_pernet_subsys;
smc_ism_init();
smc_clc_init();
rc = smc_nl_init();
if (rc)
- goto out_pernet_subsys;
+ goto out_pernet_subsys_stat;
rc = smc_pnet_init();
if (rc)
@@ -3480,6 +3480,8 @@ static int __init smc_init(void)
smc_pnet_exit();
out_nl:
smc_nl_exit();
+out_pernet_subsys_stat:
+ unregister_pernet_subsys(&smc_net_stat_ops);
out_pernet_subsys:
unregister_pernet_subsys(&smc_net_ops);
