This is a note to let you know that I've just added the patch titled

Staging: comedi: Return -EFAULT if copy_to_user() fails

to my staging git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git in the staging-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From cab36da4bf1a35739b091b73714a39a1bbd02b05 Mon Sep 17 00:00:00 2001

From: Dan Carpenter dan.carpenter@oracle.com Date: Wed, 2 Dec 2020 09:43:49 +0300 Subject: Staging: comedi: Return -EFAULT if copy_to_user() fails

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@oracle.com Cc: stable stable@vger.kernel.org Link: https://lore.kernel.org/r/X8c3pfwFy2jpy4BP@mwanda Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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. */