6.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Li Lingfeng <lilingfeng3@xxxxxxxxxx>
[ Upstream commit 570b9147deb6b07b955b55e06c714ca12a5f3e16 ]
Since md_start_sync() will be called without the protect of mddev_lock,
and it can run concurrently with array reconfiguration, traversal of rdev
in it should be protected by RCU lock.
Commit bc08041b32ab ("md: suspend array in md_start_sync() if array need
reconfiguration") added md_spares_need_change() to md_start_sync(),
casusing use of rdev without any protection.
Fix this by adding RCU lock in md_spares_need_change().
Fixes: bc08041b32ab ("md: suspend array in md_start_sync() if array need reconfiguration")
Cc: stable@xxxxxxxxxxxxxxx # 6.7+
Signed-off-by: Li Lingfeng <lilingfeng3@xxxxxxxxxx>
Signed-off-by: Song Liu <song@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240104133629.1277517-1-lilingfeng@xxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/md/md.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index d344e6fa3b26f..fbe528ed236f6 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -9277,9 +9277,14 @@ static bool md_spares_need_change(struct mddev *mddev)
{
struct md_rdev *rdev;
- rdev_for_each(rdev, mddev)
- if (rdev_removeable(rdev) || rdev_addable(rdev))
+ rcu_read_lock();
+ rdev_for_each_rcu(rdev, mddev) {
+ if (rdev_removeable(rdev) || rdev_addable(rdev)) {
+ rcu_read_unlock();
return true;
+ }
+ }
+ rcu_read_unlock();
return false;
}
--
2.43.0
