[PATCH] btrfs: Use kfree() in btrfs_ioctl_get_subvol_info()

[PATCH] btrfs: Use kfree() in btrfs_ioctl_get_subvol_info()

[Waiman Long]

In btrfs_ioctl_get_subvol_info(), there is a classic case where kzalloc()
was incorrectly paired with kzfree(). According to David Sterba, there
isn't any sensitive information in the subvol_info that needs to be
cleared before freeing. So kzfree() isn't really needed, use kfree()
instead.

Reported-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Waiman Long <longman@redhat.com>
---
 fs/btrfs/ioctl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 168deb8ef68a..e8f7c5f00894 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2692,7 +2692,7 @@ static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
 	btrfs_put_root(root);
 out_free:
 	btrfs_free_path(path);
-	kzfree(subvol_info);
+	kfree(subvol_info);
 	return ret;
 }
 
-- 
2.18.1

Re: [PATCH] btrfs: Use kfree() in btrfs_ioctl_get_subvol_info()

[David Sterba]

On Tue, Jun 16, 2020 at 11:31:59AM -0400, Waiman Long wrote:
> In btrfs_ioctl_get_subvol_info(), there is a classic case where kzalloc()
> was incorrectly paired with kzfree(). According to David Sterba, there
> isn't any sensitive information in the subvol_info that needs to be
> cleared before freeing. So kzfree() isn't really needed, use kfree()
> instead.
> 
> Reported-by: David Sterba <dsterba@suse.cz>
> Signed-off-by: Waiman Long <longman@redhat.com>

Added to the devel patch queue, thanks.