From: Niels Dossche <dossche.niels@xxxxxxxxx>
[ Upstream commit 46b348fd2d81a341b15fb3f3f986204b038f5c42 ]
alx_reinit has a lockdep assertion that the alx->mtx mutex must be held.
alx_reinit is called from two places: alx_reset and alx_change_mtu.
alx_reset does acquire alx->mtx before calling alx_reinit.
alx_change_mtu does not acquire this mutex, nor do its callers or any
path towards alx_change_mtu.
Acquire the mutex in alx_change_mtu.
The issue was introduced when the fine-grained locking was introduced
to the code to replace the RTNL. The same commit also introduced the
lockdep assertion.
Fixes: 4a5fe57e7751 ("alx: use fine-grained locking instead of RTNL")
Signed-off-by: Niels Dossche <dossche.niels@xxxxxxxxx>
Link: https://lore.kernel.org/r/20220310232707.44251-1-dossche.niels@xxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/atheros/alx/main.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/atheros/alx/main.c b/drivers/net/ethernet/atheros/alx/main.c
index 4ad3fc72e74e..a89b93cb4e26 100644
--- a/drivers/net/ethernet/atheros/alx/main.c
+++ b/drivers/net/ethernet/atheros/alx/main.c
@@ -1181,8 +1181,11 @@ static int alx_change_mtu(struct net_device *netdev, int mtu)
alx->hw.mtu = mtu;
alx->rxbuf_size = max(max_frame, ALX_DEF_RXBUF_SIZE);
netdev_update_features(netdev);
- if (netif_running(netdev))
+ if (netif_running(netdev)) {
+ mutex_lock(&alx->mtx);
alx_reinit(alx);
+ mutex_unlock(&alx->mtx);
+ }
return 0;
}
--
2.34.1
