CVE-2022-50394

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

i2c: ismt: Fix an out-of-bounds bug in ismt_access()

When the driver does not check the data from the user, the variable

'data->block[0]' may be very large to cause an out-of-bounds bug.

The following log can reveal it:

[ 33.995542] i2c i2c-1: ioctl, cmd=0x720, arg=0x7ffcb3dc3a20

[ 33.995978] ismt_smbus 0000:00:05.0: I2C_SMBUS_BLOCK_DATA: WRITE

[ 33.996475] ==================================================================

[ 33.996995] BUG: KASAN: out-of-bounds in ismt_access.cold+0x374/0x214b

[ 33.997473] Read of size 18446744073709551615 at addr ffff88810efcfdb1 by task ismt_poc/485

[ 33.999450] Call Trace:

[ 34.001849] memcpy+0x20/0x60

[ 34.002077] ismt_access.cold+0x374/0x214b

[ 34.003382] __i2c_smbus_xfer+0x44f/0xfb0

[ 34.004007] i2c_smbus_xfer+0x10a/0x390

[ 34.004291] i2cdev_ioctl_smbus+0x2c8/0x710

[ 34.005196] i2cdev_ioctl+0x5ec/0x74c

Fix this bug by checking the size of 'data

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References