[v2] Btrfs: do not overwrite error return value in the balance ioctl
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Message ID 20190108114201.1997-1-fdmanana@kernel.org
State New
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Series
  • [v2] Btrfs: do not overwrite error return value in the balance ioctl
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Commit Message

Filipe Manana Jan. 8, 2019, 11:42 a.m. UTC
From: Filipe Manana <fdmanana@suse.com>

If the call to btrfs_balance() failed we would overwrite the error
returned to user space with -EFAULT if the call to copy_to_user() failed
as well. Fix that by calling copy_to_user() only if btrfs_balance()
returned success or was canceled.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---

V2: Considered the case where balance is canceled.

 fs/btrfs/ioctl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

David Sterba Jan. 8, 2019, 3:58 p.m. UTC | #1
On Tue, Jan 08, 2019 at 11:42:01AM +0000, fdmanana@kernel.org wrote:
> From: Filipe Manana <fdmanana@suse.com>
> 
> If the call to btrfs_balance() failed we would overwrite the error
> returned to user space with -EFAULT if the call to copy_to_user() failed
> as well. Fix that by calling copy_to_user() only if btrfs_balance()
> returned success or was canceled.
> 
> Signed-off-by: Filipe Manana <fdmanana@suse.com>

Reviewed-by: David Sterba <dsterba@suse.com>

Patch
diff mbox series

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index d0da86ac53bf..8dbb4ed07da1 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4768,7 +4768,7 @@  static long btrfs_ioctl_balance(struct file *file, void __user *arg)
 	ret = btrfs_balance(fs_info, bctl, bargs);
 	bctl = NULL;
 
-	if (arg) {
+	if ((ret == 0 || ret == -ECANCELED) && arg) {
 		if (copy_to_user(arg, bargs, sizeof(*bargs)))
 			ret = -EFAULT;
 	}