During raid1 reshape operations, a use-after-free can occur in the mempool
wait queue when r1bio_pool->curr_nr drops below min_nr. This happens
because:
1. mempool_init() initializes wait queue head on stack
2. The stack-allocated wait queue is copied to conf->r1bio_pool through
structure assignment
3. wake_up() on this invalid wait queue causes panic when accessing the
stack memory that no longer exists
Fix this by properly reinitializing the mempool's wait queue using
init_waitqueue_head(), ensuring the wait queue structure remains valid
throughout the reshape operation.
Signed-off-by: Wang Jinchao <wangjinchao600@xxxxxxxxx>
---
drivers/md/raid1.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 19c5a0ce5a40..fd4ce2a4136f 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -3428,6 +3428,7 @@ static int raid1_reshape(struct mddev *mddev)
/* ok, everything is stopped */
oldpool = conf->r1bio_pool;
conf->r1bio_pool = newpool;
+ init_waitqueue_head(&conf->r1bio_pool.wait);
for (d = d2 = 0; d < conf->raid_disks; d++) {
struct md_rdev *rdev = conf->mirrors[d].rdev;
--
2.43.0
