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| author | Dan Carpenter <dan.carpenter@oracle.com> | 2017-09-22 23:43:46 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-09-25 10:57:13 +0200 |
| commit | fa1ed74eb1c233be6131ec92df21ab46499a15b6 (patch) | |
| tree | 8f45e2a37fbbe8bbdf9825c6ebe5974d29e304f0 | |
| parent | 57999d1107c1e60c2ca7088f2ac0f819e2f554b3 (diff) | |
| download | linux-fa1ed74eb1c233be6131ec92df21ab46499a15b6.tar.bz2 | |
USB: devio: Don't corrupt user memory
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>
Cc: stable <stable@vger.kernel.org>
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>
| -rw-r--r-- | drivers/usb/core/devio.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index e9326f31db8d..4664e543cf2f 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -1576,7 +1576,11 @@ static int proc_do_submiturb(struct usb_dev_state *ps, struct usbdevfs_urb *uurb 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: |