This is a note to let you know that I've just added the patch titled
media: m920x: don't use stack on USB reads
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
media-m920x-don-t-use-stack-on-usb-reads.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3e6039cb46bc7818de26fe1a284d4ae8c32a3963
Author: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
Date: Mon Dec 6 15:34:19 2021 +0100
media: m920x: don't use stack on USB reads
[ 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@xxxxxxx/
Reported-by: rkardell@xxxxxxx
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/media/usb/dvb-usb/m920x.c b/drivers/media/usb/dvb-usb/m920x.c
index 4bb5b82599a79..691e05833db19 100644
--- a/drivers/media/usb/dvb-usb/m920x.c
+++ b/drivers/media/usb/dvb-usb/m920x.c
@@ -274,6 +274,13 @@ 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. */
@@ -281,9 +288,12 @@ 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. */
