| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.13 068/160] USB: devio: Dont corrupt user memory | Date | Tue, 10 Oct 2017 21:49:56 +0200 |
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4.13-stable review patch. If anyone has any objections, please let me know.
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From: Dan Carpenter <dan.carpenter@oracle.com>
commit fa1ed74eb1c233be6131ec92df21ab46499a15b6 upstream.
The user buffer has "uurb->buffer_length" bytes. If the kernel has more information than that, we should truncate it instead of writing past the end of the user's buffer. I added a WARN_ONCE() to help the user debug the issue.
Reported-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/usb/core/devio.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -1576,7 +1576,11 @@ static int proc_do_submiturb(struct usb_ totlen += isopkt[u].length; } u *= sizeof(struct usb_iso_packet_descriptor); - uurb->buffer_length = totlen; + if (totlen <= uurb->buffer_length) + uurb->buffer_length = totlen; + else + WARN_ONCE(1, "uurb->buffer_length is too short %d vs %d", + totlen, uurb->buffer_length); break; default:
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