From cb3560e8eab1dfa1cac1ed52631adf8ec6ff2cd5 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 20 May 2026 16:26:22 +0200 Subject: [PATCH] USB: serial: digi_acceleport: fix memory corruption with small endpoints Add the missing bulk-out buffer size sanity checks to avoid out-of-bounds memory accesses or slab corruption should a malicious device report smaller buffers than expected. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold --- drivers/usb/serial/digi_acceleport.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/drivers/usb/serial/digi_acceleport.c b/drivers/usb/serial/digi_acceleport.c index d515df045c4c..c481208255eb 100644 --- a/drivers/usb/serial/digi_acceleport.c +++ b/drivers/usb/serial/digi_acceleport.c @@ -1229,15 +1229,34 @@ static int digi_port_init(struct usb_serial_port *port, unsigned port_num) static int digi_startup(struct usb_serial *serial) { struct digi_serial *serial_priv; + int oob_port_num; int ret; + int i; + + /* + * The port bulk-out buffers must be large enough for header and + * buffered data. + */ + for (i = 0; i < serial->type->num_ports; i++) { + if (serial->port[i]->bulk_out_size < DIGI_OUT_BUF_SIZE + 2) + return -EINVAL; + } + + /* + * The OOB port bulk-out buffer must be large enough for the two + * commands in digi_set_modem_signals(). + */ + oob_port_num = serial->type->num_ports; + if (serial->port[oob_port_num]->bulk_out_size < 8) + return -EINVAL; serial_priv = kzalloc_obj(*serial_priv); if (!serial_priv) return -ENOMEM; spin_lock_init(&serial_priv->ds_serial_lock); - serial_priv->ds_oob_port_num = serial->type->num_ports; - serial_priv->ds_oob_port = serial->port[serial_priv->ds_oob_port_num]; + serial_priv->ds_oob_port_num = oob_port_num; + serial_priv->ds_oob_port = serial->port[oob_port_num]; ret = digi_port_init(serial_priv->ds_oob_port, serial_priv->ds_oob_port_num);