4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jozef Balga <jozef.balga@xxxxxxxxx>
[ Upstream commit 312f73b648626a0526a3aceebb0a3192aaba05ce ]
When less than 3 bytes are written to the device, memcpy is called with
negative array size which leads to buffer overflow and kernel panic. This
patch adds a condition and returns -EOPNOTSUPP instead.
Fixes bugzilla issue 64871
[mchehab+samsung@xxxxxxxxxx: fix a merge conflict and changed the
condition to match the patch's comment, e. g. len == 3 could
also be valid]
Signed-off-by: Jozef Balga <jozef.balga@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/media/usb/dvb-usb-v2/af9035.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/media/usb/dvb-usb-v2/af9035.c
+++ b/drivers/media/usb/dvb-usb-v2/af9035.c
@@ -402,8 +402,10 @@ static int af9035_i2c_master_xfer(struct
if (msg[0].addr == state->af9033_i2c_addr[1])
reg |= 0x100000;
- ret = af9035_wr_regs(d, reg, &msg[0].buf[3],
- msg[0].len - 3);
+ ret = (msg[0].len >= 3) ? af9035_wr_regs(d, reg,
+ &msg[0].buf[3],
+ msg[0].len - 3)
+ : -EOPNOTSUPP;
} else {
/* I2C write */
u8 buf[MAX_XFER_SIZE];
