net: Add module reference to FIB notifiers
When a listener registers to the FIB notification chain it receives a
dump of the FIB entries and rules from existing address families by
invoking their dump operations.
While we call into these modules we need to make sure they aren't
removed. Do that by increasing their reference count before invoking
their dump operations and decrease it afterwards.
Fixes: 04b1d4e50e82 ("net: core: Make the FIB notification chain generic")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/fib_notifier.c b/net/core/fib_notifier.c
index 292aab8..4fc202d 100644
--- a/net/core/fib_notifier.c
+++ b/net/core/fib_notifier.c
@@ -2,6 +2,7 @@
#include <linux/notifier.h>
#include <linux/rcupdate.h>
#include <linux/kernel.h>
+#include <linux/module.h>
#include <linux/init.h>
#include <net/net_namespace.h>
#include <net/fib_notifier.h>
@@ -33,8 +34,12 @@
rtnl_lock();
for_each_net(net) {
- list_for_each_entry(ops, &net->fib_notifier_ops, list)
+ list_for_each_entry(ops, &net->fib_notifier_ops, list) {
+ if (!try_module_get(ops->owner))
+ continue;
fib_seq += ops->fib_seq_read(net);
+ module_put(ops->owner);
+ }
}
rtnl_unlock();
@@ -46,8 +51,12 @@
struct fib_notifier_ops *ops;
list_for_each_entry_rcu(ops, &net->fib_notifier_ops, list) {
- int err = ops->fib_dump(net, nb);
+ int err;
+ if (!try_module_get(ops->owner))
+ continue;
+ err = ops->fib_dump(net, nb);
+ module_put(ops->owner);
if (err)
return err;
}