diff options
| author | Johan Hovold <johan@kernel.org> | 2026-05-22 16:19:50 +0200 |
|---|---|---|
| committer | Johan Hovold <johan@kernel.org> | 2026-05-23 09:07:18 +0200 |
| commit | 4085f0dbb1ce2251c9a5938d693de6593f0ab2bd (patch) | |
| tree | 7a4c25cbd134dc6eea2e73c4a71f5807cfddfa1a | |
| parent | e1a9d791fd66ab2431b9e6f6f835823809869047 (diff) | |
USB: serial: mxuport: fix memory corruption with small endpoint
Make sure that the bulk-out endpoint max packet size is at least eight
bytes to avoid user-controlled slab corruption should a malicious device
report a smaller size.
Fixes: ee467a1f2066 ("USB: serial: add Moxa UPORT 12XX/14XX/16XX driver")
Cc: stable@vger.kernel.org # 3.14
Cc: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
| -rw-r--r-- | drivers/usb/serial/mxuport.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/usb/serial/mxuport.c b/drivers/usb/serial/mxuport.c index ad5fdf55a02e..c9b9928c473a 100644 --- a/drivers/usb/serial/mxuport.c +++ b/drivers/usb/serial/mxuport.c @@ -962,6 +962,14 @@ static int mxuport_calc_num_ports(struct usb_serial *serial, */ BUILD_BUG_ON(ARRAY_SIZE(epds->bulk_out) < 16); + /* + * The bulk-out buffers must be large enough for the four-byte header + * (and following data), but assume anything smaller than eight bytes + * is broken. + */ + if (usb_endpoint_maxp(epds->bulk_out[0]) < 8) + return -EINVAL; + for (i = 1; i < num_ports; ++i) epds->bulk_out[i] = epds->bulk_out[0]; |