From: Mauro Carvalho Chehab mchehab+huawei@kernel.org
[ Upstream commit a2ab06d7c4d6bfd0b545a768247a70463e977e27 ]
Using stack-allocated pointers for USB message data don't work. This driver is almost OK with that, except for the I2C read logic.
Fix it by using a temporary read buffer, just like on all other calls to m920x_read().
Link: https://lore.kernel.org/all/ccc99e48-de4f-045e-0fe4-61e3118e3f74@mida.se/ Reported-by: rkardell@mida.se Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/media/usb/dvb-usb/m920x.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/media/usb/dvb-usb/m920x.c b/drivers/media/usb/dvb-usb/m920x.c index eafc5c82467f4..5b806779e2106 100644 --- a/drivers/media/usb/dvb-usb/m920x.c +++ b/drivers/media/usb/dvb-usb/m920x.c @@ -284,6 +284,13 @@ static int m920x_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int nu /* Should check for ack here, if we knew how. */ } if (msg[i].flags & I2C_M_RD) { + char *read = kmalloc(1, GFP_KERNEL); + if (!read) { + ret = -ENOMEM; + kfree(read); + goto unlock; + } + for (j = 0; j < msg[i].len; j++) { /* Last byte of transaction? * Send STOP, otherwise send ACK. */ @@ -291,9 +298,12 @@ static int m920x_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int nu
if ((ret = m920x_read(d->udev, M9206_I2C, 0x0, 0x20 | stop, - &msg[i].buf[j], 1)) != 0) + read, 1)) != 0) goto unlock; + msg[i].buf[j] = read[0]; } + + kfree(read); } else { for (j = 0; j < msg[i].len; j++) { /* Last byte of transaction? Then send STOP. */