[media] firewire: firedtv-avc: fix more potential buffer overflow

"program_info_length" is user controlled and can go up to 4095.  The
operand[] array has 509 bytes so we need to add a limit here to prevent
buffer overflows.

The " - 4" in the limit check is because we have 4 bytes more data to
add after the memcpy().

[mchehab@osg.samsung.com: as I merged the version 1 of the patch, I needed
 to rebase to apply just the differences between v1 and v2]
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This commit is contained in:
Dan Carpenter 2014-09-09 09:11:23 -03:00 committed by Mauro Carvalho Chehab
parent cf3b576d52
commit 7ac95cf59d

View file

@ -1157,7 +1157,7 @@ int avc_ca_pmt(struct firedtv *fdtv, char *msg, int length)
if (pmt_cmd_id != 1 && pmt_cmd_id != 4)
dev_err(fdtv->device,
"invalid pmt_cmd_id %d\n", pmt_cmd_id);
if (program_info_length > sizeof(c->operand) - write_pos) {
if (program_info_length > sizeof(c->operand) - 4 - write_pos) {
ret = -EINVAL;
goto out;
}
@ -1184,7 +1184,8 @@ int avc_ca_pmt(struct firedtv *fdtv, char *msg, int length)
dev_err(fdtv->device, "invalid pmt_cmd_id %d "
"at stream level\n", pmt_cmd_id);
if (es_info_length > sizeof(c->operand) - write_pos) {
if (es_info_length > sizeof(c->operand) - 4 -
write_pos) {
ret = -EINVAL;
goto out;
}