[PATCH v2 15/26] drbd: Balance RCU calls in drbd_adm_dump_devices()

Bart Van Assche
2026-03-25T21:46:11Z

Make drbd_adm_dump_devices() call rcu_read_lock() before
rcu_read_unlock() is called. This has been detected by the Clang
thread-safety analyzer.

Tested-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Fixes: a55bbd375d18 ("drbd: Backport the "status" command")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
drivers/block/drbd/drbd_nl.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index e18fa260a662..1f8ffdf9b24e 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -3443,8 +3443,10 @@ int drbd_adm_dump_devices(struct sk_buff *skb, struct netlink_callback *cb)
if (resource_filter) {
retcode = ERR_RES_NOT_KNOWN;
resource = drbd_find_resource(nla_data(resource_filter));
- if (!resource)
+ if (!resource) {
+ rcu_read_lock();
goto put_result;
+ }
cb->args[0] = (long)resource;
}
}
@@ -3693,8 +3695,10 @@ int drbd_adm_dump_peer_devices(struct sk_buff *skb, struct netlink_callback *cb)
if (resource_filter) {
retcode = ERR_RES_NOT_KNOWN;
resource = drbd_find_resource(nla_data(resource_filter));
- if (!resource)
+ if (!resource) {
+ rcu_read_lock();
goto put_result;
+ }
}
cb->args[0] = (long)resource;
}