diff options
| author | Jeremy Compostella <jeremy.compostella@intel.com> | 2017-11-15 12:31:44 -0700 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2018-01-17 15:35:21 +0100 |
| commit | 89c6efa61f5709327ecfa24bff18e57a4e80c7fa (patch) | |
| tree | 7b347b13836cd294f38a1b0cd5e0d02bc8e33a9b /drivers/i2c/i2c-core-smbus.c | |
| parent | e0638fa400eaccf9fa8060f67140264c4e276552 (diff) | |
i2c: core-smbus: prevent stack corruption on read I2C_BLOCK_DATA
On a I2C_SMBUS_I2C_BLOCK_DATA read request, if data->block[0] is
greater than I2C_SMBUS_BLOCK_MAX + 1, the underlying I2C driver writes
data out of the msgbuf1 array boundary.
It is possible from a user application to run into that issue by
calling the I2C_SMBUS ioctl with data.block[0] greater than
I2C_SMBUS_BLOCK_MAX + 1.
This patch makes the code compliant with
Documentation/i2c/dev-interface by raising an error when the requested
size is larger than 32 bytes.
Call Trace:
[<ffffffff8139f695>] dump_stack+0x67/0x92
[<ffffffff811802a4>] panic+0xc5/0x1eb
[<ffffffff810ecb5f>] ? vprintk_default+0x1f/0x30
[<ffffffff817456d3>] ? i2cdev_ioctl_smbus+0x303/0x320
[<ffffffff8109a68b>] __stack_chk_fail+0x1b/0x20
[<ffffffff817456d3>] i2cdev_ioctl_smbus+0x303/0x320
[<ffffffff81745aed>] i2cdev_ioctl+0x4d/0x1e0
[<ffffffff811f761a>] do_vfs_ioctl+0x2ba/0x490
[<ffffffff81336e43>] ? security_file_ioctl+0x43/0x60
[<ffffffff811f7869>] SyS_ioctl+0x79/0x90
[<ffffffff81a22e97>] entry_SYSCALL_64_fastpath+0x12/0x6a
Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
Diffstat (limited to 'drivers/i2c/i2c-core-smbus.c')
| -rw-r--r-- | drivers/i2c/i2c-core-smbus.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c index 4bb9927afd01..a1082c04ac5c 100644 --- a/drivers/i2c/i2c-core-smbus.c +++ b/drivers/i2c/i2c-core-smbus.c @@ -397,16 +397,17 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, the underlying bus driver */ break; case I2C_SMBUS_I2C_BLOCK_DATA: + if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { + dev_err(&adapter->dev, "Invalid block %s size %d\n", + read_write == I2C_SMBUS_READ ? "read" : "write", + data->block[0]); + return -EINVAL; + } + if (read_write == I2C_SMBUS_READ) { msg[1].len = data->block[0]; } else { msg[0].len = data->block[0] + 1; - if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { - dev_err(&adapter->dev, - "Invalid block write size %d\n", - data->block[0]); - return -EINVAL; - } for (i = 1; i <= data->block[0]; i++) msgbuf0[i] = data->block[i]; } |