Commit 88be2439 authored Aug 21, 2018 by Jozef Balga Committed by Greg Kroah-Hartman Oct 20, 2018

media: af9035: prevent buffer overflow on write



[ 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@kernel.org: 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@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 8263087b

drivers/media/usb/dvb-usb-v2/af9035.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -402,8 +402,10 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap,
		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];