From 8a28d43a7ce7ae73eada022e17bf7f40c5c421ae Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 6 Mar 2023 09:36:25 +1100 Subject: [PATCH] md: avoid signed overflow in slot_store() [ Upstream commit 3bc57292278a0b6ac4656cad94c14f2453344b57 ] slot_store() uses kstrtouint() to get a slot number, but stores the result in an "int" variable (by casting a pointer). This can result in a negative slot number if the unsigned int value is very large. A negative number means that the slot is empty, but setting a negative slot number this way will not remove the device from the array. I don't think this is a serious problem, but it could cause confusion and it is best to fix it. Reported-by: Dan Carpenter Signed-off-by: NeilBrown Signed-off-by: Song Liu Signed-off-by: Sasha Levin --- drivers/md/md.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/md/md.c b/drivers/md/md.c index aa2993d5d5d38..64558991ce0a0 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -3082,6 +3082,9 @@ slot_store(struct md_rdev *rdev, const char *buf, size_t len) err = kstrtouint(buf, 10, (unsigned int *)&slot); if (err < 0) return err; + if (slot < 0) + /* overflow */ + return -ENOSPC; } if (rdev->mddev->pers && slot == -1) { /* Setting 'slot' on an active array requires also -- 2.39.5