Return -EFAULT on error instead of the number of bytes remaining to be copied. Fixes: bac42fb21259 ("comedi: get rid of compat_alloc_user_space() mess in COMEDI_CMD{,TEST} compat") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> --- Hi Al, this goes through your tree. drivers/staging/comedi/comedi_fops.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index d99231c737fb..80d74cce2a01 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -2987,7 +2987,9 @@ static int put_compat_cmd(struct comedi32_cmd_struct __user *cmd32, v32.chanlist_len = cmd->chanlist_len; v32.data = ptr_to_compat(cmd->data); v32.data_len = cmd->data_len; - return copy_to_user(cmd32, &v32, sizeof(v32)); + if (copy_to_user(cmd32, &v32, sizeof(v32))) + return -EFAULT; + return 0; } /* Handle 32-bit COMEDI_CMD ioctl. */ -- 2.29.2