6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
[ Upstream commit e361560a7912958ba3059f51e7dd21612d119169 ]
The cited commit forgot to add netdev_rename_lock in one of the
error paths in dev_change_name().
Let's hold netdev_rename_lock before restoring the old dev->name.
Fixes: 0840556e5a3a ("net: Protect dev->name by seqlock.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Link: https://patch.msgid.link/20250115095545.52709-2-kuniyu@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/core/dev.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/core/dev.c b/net/core/dev.c
index 1867a6a8d76da..9bdb8fe5ffaa5 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1279,7 +1279,9 @@ int dev_change_name(struct net_device *dev, const char *newname)
rollback:
ret = device_rename(&dev->dev, dev->name);
if (ret) {
+ write_seqlock_bh(&netdev_rename_lock);
memcpy(dev->name, oldname, IFNAMSIZ);
+ write_sequnlock_bh(&netdev_rename_lock);
WRITE_ONCE(dev->name_assign_type, old_assign_type);
up_write(&devnet_rename_sem);
return ret;
--
2.39.5
