CVE-2022-50406

/// Technical description

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

iomap: iomap: fix memory corruption when recording errors during writeback

Every now and then I see this crash on arm64:

Unable to handle kernel NULL pointer dereference at virtual address 00000000000000f8

Buffer I/O error on dev dm-0, logical block 8733687, async page read

Mem abort info:

ESR = 0x0000000096000006

EC = 0x25: DABT (current EL), IL = 32 bits

SET = 0, FnV = 0

EA = 0, S1PTW = 0

FSC = 0x06: level 2 translation fault

Data abort info:

ISV = 0, ISS = 0x00000006

CM = 0, WnR = 0

user pgtable: 64k pages, 42-bit VAs, pgdp=0000000139750000

[00000000000000f8] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000, pmd=0000000000000000

Internal error: Oops: 96000006 [#1] PREEMPT SMP

Buffer I/O error on dev dm-0, logical block 8733688, async page read

Dumping ftrace buffer:

Buffer I/O error on dev dm-0, logical block 8733689, async page read

(ftrace buffer empty)

XFS (dm-0): log I/O error

/// 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