| From | Luis Henriques <> | Subject | [PATCH 3.16.y-ckt 016/185] [media] cx24116: fix a buffer overflow when checking userspace params | Date | Wed, 15 Jul 2015 10:10:11 +0100 |
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3.16.7-ckt15 -stable review patch. If anyone has any objections, please let me know.
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From: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
commit 1fa2337a315a2448c5434f41e00d56b01a22283c upstream.
The maximum size for a DiSEqC command is 6, according to the userspace API. However, the code allows to write up much more values: drivers/media/dvb-frontends/cx24116.c:983 cx24116_send_diseqc_msg() error: buffer overflow 'd->msg' 6 <= 23
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/media/dvb-frontends/cx24116.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/media/dvb-frontends/cx24116.c b/drivers/media/dvb-frontends/cx24116.c index 2916d7c74a1d..7bc68b355c0b 100644 --- a/drivers/media/dvb-frontends/cx24116.c +++ b/drivers/media/dvb-frontends/cx24116.c @@ -963,6 +963,10 @@ static int cx24116_send_diseqc_msg(struct dvb_frontend *fe, struct cx24116_state *state = fe->demodulator_priv; int i, ret; + /* Validate length */ + if (d->msg_len > sizeof(d->msg)) + return -EINVAL; + /* Dump DiSEqC message */ if (debug) { printk(KERN_INFO "cx24116: %s(", __func__); @@ -974,10 +978,6 @@ static int cx24116_send_diseqc_msg(struct dvb_frontend *fe, printk(") toneburst=%d\n", toneburst); } - /* Validate length */ - if (d->msg_len > (CX24116_ARGLEN - CX24116_DISEQC_MSGOFS)) - return -EINVAL; - /* DiSEqC message */ for (i = 0; i < d->msg_len; i++) state->dsec_cmd.args[CX24116_DISEQC_MSGOFS + i] = d->msg[i];
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