CVE-2021-47481

/// Technical description

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

RDMA/mlx5: Initialize the ODP xarray when creating an ODP MR

Normally the zero fill would hide the missing initialization, but an

errant set to desc_size in reg_create() causes a crash:

BUG: unable to handle page fault for address: 0000000800000000

PGD 0 P4D 0

Oops: 0000 [#1] SMP PTI

CPU: 5 PID: 890 Comm: ib_write_bw Not tainted 5.15.0-rc4+ #47

Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014

RIP: 0010:mlx5_ib_dereg_mr+0x14/0x3b0 [mlx5_ib]

Code: 48 63 cd 4c 89 f7 48 89 0c 24 e8 37 30 03 e1 48 8b 0c 24 eb a0 90 0f 1f 44 00 00 41 56 41 55 41 54 55 53 48 89 fb 48 83 ec 30 <48> 8b 2f 65 48 8b 04 25 28 00 00 00 48 89 44 24 28 31 c0 8b 87 c8

RSP: 0018:ffff88811afa3a60 EFLAGS: 00010286

RAX: 000000000000001c RBX: 0000000800000000 RCX: 0000000000000000

RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000800000000

RBP: 0000000800000000 R

/// 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