Date: Sat, 26 Dec 2009 01:47:12 +0100 (CET) From: Stefan Richter Subject: firedtv: add missing NULL pointer check If there is ever going to be a FireDTV or FloppyDTV firmware which does not provide a minimal ASCII textual descriptor for Model_Id --- or if the descriptor is provided indirectly in a descriptor directory --- the ieee1394 variant of the device probe of firedtv would dereference a NULL pointer. The firewire variant of firedtv's device probe is not affected. The fix makes sure that such an unexpected firmware is safely recognized by fdtv_alloc as an unknown firmware. Signed-off-by: Stefan Richter --- drivers/media/dvb/firewire/firedtv-1394.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) Index: linux-2.6.33-rc2/drivers/media/dvb/firewire/firedtv-1394.c =================================================================== --- linux-2.6.33-rc2.orig/drivers/media/dvb/firewire/firedtv-1394.c +++ linux-2.6.33-rc2/drivers/media/dvb/firewire/firedtv-1394.c @@ -193,9 +193,13 @@ static int node_probe(struct device *dev int kv_len, err; void *kv_str; - kv_len = (ud->model_name_kv->value.leaf.len - 2) * sizeof(quadlet_t); - kv_str = CSR1212_TEXTUAL_DESCRIPTOR_LEAF_DATA(ud->model_name_kv); - + if (ud->model_name_kv) { + kv_len = (ud->model_name_kv->value.leaf.len - 2) * 4; + kv_str = CSR1212_TEXTUAL_DESCRIPTOR_LEAF_DATA(ud->model_name_kv); + } else { + kv_len = 0; + kv_str = NULL; + } fdtv = fdtv_alloc(dev, &fdtv_1394_backend, kv_str, kv_len); if (!fdtv) return -ENOMEM;