The patch below does not apply to the 5.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 7ec4cdb321738d44ae5d405e7b6ac73dfbf99caa Mon Sep 17 00:00:00 2001 From: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Date: Mon, 25 Jul 2022 22:49:25 +0900 Subject: [PATCH] mtd: core: check partition before dereference

syzbot is reporting NULL pointer dereference at mtd_check_of_node() [1], for mtdram test device (CONFIG_MTD_MTDRAM) is not partition.

Link: https://syzkaller.appspot.com/bug?extid=fe013f55a2814a9e8cfd [1] Reported-by: syzbot syzbot+fe013f55a2814a9e8cfd@syzkaller.appspotmail.com Reported-by: kernel test robot oliver.sang@intel.com Fixes: ad9b10d1eaada169 ("mtd: core: introduce of support for dynamic partitions") Signed-off-by: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp CC: stable@vger.kernel.org Signed-off-by: Richard Weinberger richard@nod.at

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index 6fafea80fd98..a9b8be9f40dc 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -559,6 +559,8 @@ static void mtd_check_of_node(struct mtd_info *mtd) return;

/* Check if a partitions node exist */ + if (!mtd_is_partition(mtd)) + return; parent = mtd->parent; parent_dn = dev_of_node(&parent->dev); if (!parent_dn)