N/A - CVE-2021-47561

Executive Summary

Informations
Name	CVE-2021-47561	First vendor Publication	2024-05-24
Vendor	Cve	Last vendor Modification	2024-05-24

Security-Database Scoring CVSS v3

Cvss vector : N/A
Overall CVSS Score	NA
Base Score	NA	Environmental Score	NA
impact SubScore	NA	Temporal Score	NA
Exploitabality Sub Score	NA

Calculate full CVSS 3.0 Vectors scores

Security-Database Scoring CVSS v2

Cvss vector :
Cvss Base Score	N/A	Attack Range	N/A
Cvss Impact Score	N/A	Attack Complexity	N/A
Cvss Expoit Score	N/A	Authentication	N/A
Calculate full CVSS 2.0 Vectors scores

Detail

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

i2c: virtio: disable timeout handling

If a timeout is hit, it can result is incorrect data on the I2C bus and/or memory corruptions in the guest since the device can still be operating on the buffers it was given while the guest has freed them.

Here is, for example, the start of a slub_debug splat which was triggered on the next transfer after one transfer was forced to timeout by setting a breakpoint in the backend (rust-vmm/vhost-device):

BUG kmalloc-1k (Not tainted): Poison overwritten
First byte 0x1 instead of 0x6b
Allocated in virtio_i2c_xfer+0x65/0x35c age=350 cpu=0 pid=29
__kmalloc+0xc2/0x1c9
virtio_i2c_xfer+0x65/0x35c
__i2c_transfer+0x429/0x57d
i2c_transfer+0x115/0x134
i2cdev_ioctl_rdwr+0x16a/0x1de
i2cdev_ioctl+0x247/0x2ed
vfs_ioctl+0x21/0x30
sys_ioctl+0xb18/0xb41
Freed in virtio_i2c_xfer+0x32e/0x35c age=244 cpu=0 pid=29
kfree+0x1bd/0x1cc
virtio_i2c_xfer+0x32e/0x35c
__i2c_transfer+0x429/0x57d
i2c_transfer+0x115/0x134
i2cdev_ioctl_rdwr+0x16a/0x1de
i2cdev_ioctl+0x247/0x2ed
vfs_ioctl+0x21/0x30
sys_ioctl+0xb18/0xb41

There is no simple fix for this (the driver would have to always create bounce buffers and hold on to them until the device eventually returns the buffers), so just disable the timeout support for now.