CVE-2022-50282

/// Technical description

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

chardev: fix error handling in cdev_device_add()

While doing fault injection test, I got the following report:

------------[ cut here ]------------

kobject: '(null)' (0000000039956980): is not initialized, yet kobject_put() is being called.

WARNING: CPU: 3 PID: 6306 at kobject_put+0x23d/0x4e0

CPU: 3 PID: 6306 Comm: 283 Tainted: G W 6.1.0-rc2-00005-g307c1086d7c9 #1253

Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014

RIP: 0010:kobject_put+0x23d/0x4e0

Call Trace:

<TASK>

cdev_device_add+0x15e/0x1b0

__iio_device_register+0x13b4/0x1af0 [industrialio]

__devm_iio_device_register+0x22/0x90 [industrialio]

max517_probe+0x3d8/0x6b4 [max517]

i2c_device_probe+0xa81/0xc00

When device_add() is injected fault and returns error, if dev->devt is not set,

cdev_add() is not called, cdev_del() is not needed. Fix this by checking dev->devt

in error path.

/// 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