[PATCH 5.15 173/230] btrfs: fix error pointer dereference in btrfs_ioctl_rm_dev_v2()

Greg Kroah-Hartman
2022-07-11T10:04:54Z

From: Dan Carpenter <dan.carpenter@oracle.com>

commit d815b3f2f273537cb8afaf5ab11a46851f6c03e5 upstream.

If memdup_user() fails the error handing will crash when it tries
to kfree() an error pointer. Just return directly because there is
no cleanup required.

Fixes: 1a15eb724aae ("btrfs: use btrfs_get_dev_args_from_path in dev removal ioctls")
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/btrfs/ioctl.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3231,10 +3231,8 @@ static long btrfs_ioctl_rm_dev_v2(struct
return -EPERM;

vol_args = memdup_user(arg, sizeof(*vol_args));
- if (IS_ERR(vol_args)) {
- ret = PTR_ERR(vol_args);
- goto out;
- }
+ if (IS_ERR(vol_args))
+ return PTR_ERR(vol_args);

if (vol_args->flags & ~BTRFS_DEVICE_REMOVE_ARGS_MASK) {
ret = -EOPNOTSUPP;