Currently, netconsole cleans up the netpoll structure before disabling
the target. This approach can lead to race conditions, as message
senders (write_ext_msg() and write_msg()) check if the target is
enabled before using netpoll.
This patch reverses the order of operations:
1. Disable the target
2. Clean up the netpoll structure
This change eliminates the potential race condition, ensuring that
no messages are sent through a partially cleaned-up netpoll structure.
Signed-off-by: Breno Leitao <leitao@debian.org>
---
drivers/net/netconsole.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 5ef680cf994a..9c09293b5258 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -973,6 +973,7 @@ static int netconsole_netdev_event(struct notifier_block *this,
/* rtnl_lock already held
* we might sleep in __netpoll_cleanup()
*/
+ nt->enabled = false;
spin_unlock_irqrestore(&target_list_lock, flags);
__netpoll_cleanup(&nt->np);
@@ -980,7 +981,6 @@ static int netconsole_netdev_event(struct notifier_block *this,
spin_lock_irqsave(&target_list_lock, flags);
netdev_put(nt->np.dev, &nt->np.dev_tracker);
nt->np.dev = NULL;
- nt->enabled = false;
stopped = true;
netconsole_target_put(nt);
goto restart;
--
2.43.0