From 825711e00117fc686ab89ac36a9a7b252dc349c6 Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Wed, 9 Oct 2024 09:49:14 +0800 Subject: [PATCH] md/raid10: fix null ptr dereference in raid10_size() In raid10_run() if raid10_set_queue_limits() succeed, the return value is set to zero, and if following procedures failed raid10_run() will return zero while mddev->private is still NULL, causing null ptr dereference in raid10_size(). Fix the problem by only overwrite the return value if raid10_set_queue_limits() failed. Fixes: 3d8466ba68d4 ("md/raid10: use the atomic queue limit update APIs") Cc: stable@vger.kernel.org Reported-and-tested-by: ValdikSS Closes: https://lore.kernel.org/all/0dd96820-fe52-4841-bc58-dbf14d6bfcc8@valdikss.org.ru/ Signed-off-by: Yu Kuai Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20241009014914.1682037-1-yukuai1@huaweicloud.com Signed-off-by: Song Liu --- drivers/md/raid10.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index f3bf1116794a..862b1fb71d86 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -4061,9 +4061,12 @@ static int raid10_run(struct mddev *mddev) } if (!mddev_is_dm(conf->mddev)) { - ret = raid10_set_queue_limits(mddev); - if (ret) + int err = raid10_set_queue_limits(mddev); + + if (err) { + ret = err; goto out_free_conf; + } } /* need to check that every block has at least one working mirror */