diff options
| author | Deepak Sharma <deepak.sharma.472935@gmail.com> | 2025-09-26 20:28:11 +0530 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.com> | 2025-10-14 11:46:49 +0200 |
| commit | 362f21536966d7039da1de762f28f4ad44565acc (patch) | |
| tree | e0e2767018b5beec65ed4d34042d86467f92c8cd | |
| parent | 50f1f782f8d621a90108340c632bcb6ab4307d2e (diff) | |
HID: cp2112: Add parameter validation to data length
Syzkaller reported a stack OOB access in cp2112_write_req caused by lack
of parameter validation for the user input in I2C SMBUS ioctl in cp2112
driver
Add the parameter validation for the data->block[0] to be bounded by
I2C_SMBUS_BLOCK_MAX + the additional compatibility padding
[jkosina@suse.com: fix whitespace damage]
Reported-by: syzbot+7617e19c8a59edfbd879@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=7617e19c8a59edfbd879
Tested-by: syzbot+7617e19c8a59edfbd879@syzkaller.appspotmail.com
Signed-off-by: Deepak Sharma <deepak.sharma.472935@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
| -rw-r--r-- | drivers/hid/hid-cp2112.c | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c index 5a95ea3bec98..803b883ae875 100644 --- a/drivers/hid/hid-cp2112.c +++ b/drivers/hid/hid-cp2112.c @@ -689,7 +689,14 @@ static int cp2112_xfer(struct i2c_adapter *adap, u16 addr, count = cp2112_write_read_req(buf, addr, read_length, command, NULL, 0); } else { - count = cp2112_write_req(buf, addr, command, + /* Copy starts from data->block[1] so the length can + * be at max I2C_SMBUS_CLOCK_MAX + 1 + */ + + if (data->block[0] > I2C_SMBUS_BLOCK_MAX + 1) + count = -EINVAL; + else + count = cp2112_write_req(buf, addr, command, data->block + 1, data->block[0]); } @@ -700,7 +707,14 @@ static int cp2112_xfer(struct i2c_adapter *adap, u16 addr, I2C_SMBUS_BLOCK_MAX, command, NULL, 0); } else { - count = cp2112_write_req(buf, addr, command, + /* data_length here is data->block[0] + 1 + * so make sure that the data->block[0] is + * less than or equals I2C_SMBUS_BLOCK_MAX + 1 + */ + if (data->block[0] > I2C_SMBUS_BLOCK_MAX + 1) + count = -EINVAL; + else + count = cp2112_write_req(buf, addr, command, data->block, data->block[0] + 1); } @@ -709,7 +723,14 @@ static int cp2112_xfer(struct i2c_adapter *adap, u16 addr, size = I2C_SMBUS_BLOCK_DATA; read_write = I2C_SMBUS_READ; - count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX, + /* data_length is data->block[0] + 1, so + * so data->block[0] should be less than or + * equal to the I2C_SMBUS_BLOCK_MAX + 1 + */ + if (data->block[0] > I2C_SMBUS_BLOCK_MAX + 1) + count = -EINVAL; + else + count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX, command, data->block, data->block[0] + 1); break; |