CVE-2023-53576

/// Technical description

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

null_blk: Always check queue mode setting from configfs

Make sure to check device queue mode in the null_validate_conf() and

return error for NULL_Q_RQ as we don't allow legacy I/O path, without

this patch we get OOPs when queue mode is set to 1 from configfs,

following are repro steps :-

modprobe null_blk nr_devices=0

mkdir config/nullb/nullb0

echo 1 > config/nullb/nullb0/memory_backed

echo 4096 > config/nullb/nullb0/blocksize

echo 20480 > config/nullb/nullb0/size

echo 1 > config/nullb/nullb0/queue_mode

echo 1 > config/nullb/nullb0/power

Entering kdb (current=0xffff88810acdd080, pid 2372) on processor 42 Oops: (null)

due to oops @ 0xffffffffc041c329

CPU: 42 PID: 2372 Comm: sh Tainted: G O N 6.3.0-rc5lblk+ #5

Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014

RIP: 0010:null_add_dev.part.0+0xd9/0x720 [null_blk]

Code: 01 00 00 85 d2 0f 85

/// 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