From 3bc57292278a0b6ac4656cad94c14f2453344b57 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.de>
Date: Mon, 6 Mar 2023 09:36:25 +1100
Subject: [PATCH] md: avoid signed overflow in slot_store()
Git-commit: 3bc57292278a0b6ac4656cad94c14f2453344b57
Patch-mainline: v6.3-rc3
References: git-fixes
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 <error27@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/md.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index f5480778e2f7..39e49e5d7182 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3128,6 +3128,9 @@ 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
--
2.35.3