mainline inclusion from mainline-v6.9-rc1 commit 570b9147deb6b07b955b55e06c714ca12a5f3e16 bugzilla: https://gitee.com/openeuler/kernel/issues/IAZESX

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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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@vger.kernel.org # 6.7+ Signed-off-by: Li Lingfeng lilingfeng3@huawei.com Signed-off-by: Song Liu song@kernel.org Link: https://lore.kernel.org/r/20240104133629.1277517-1-lilingfeng@huaweicloud.co... Signed-off-by: Li Lingfeng lilingfeng3@huawei.com --- 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 29e105845772..31b275bad88c 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; }