From: NeilBrown neilb@suse.de
[ 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 error27@gmail.com Signed-off-by: NeilBrown neilb@suse.de Signed-off-by: Song Liu song@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/md/md.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/md/md.c b/drivers/md/md.c index 272cc5d14906f..beab84f0c585c 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -3131,6 +3131,9 @@ 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