CVE-2022-50394: i2c: ismt: Fix an out-of-bounds bug in ismt_access()

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-09-18 · updated 2026-08-04
Weakness: CWE-125

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->block[0]' first.

Affected products

Linux kernel: from 3.9 before 4.9.337; from 4.10 before 4.14.303; from 4.15 before 4.19.270; from 4.20 before 5.4.229; from 5.5 before 5.10.163; from 5.11 before 5.15.86 — fixed in 4.14.303, 4.19.270, 4.9.337, 5.10.163, 5.15.86, 5.4.229

How to fix

Upgrade to a fixed version: Linux kernel 4.14.303, 4.19.270, 4.9.337, 5.10.163. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2022-50394 or the next vulnerability affects your stack