4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jozef Balga jozef.balga@gmail.com
[ 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 --- 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 @@ -389,8 +389,10 @@ static int af9035_i2c_master_xfer(struct msg[0].addr == (state->af9033_i2c_addr[1] >> 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];