CVE-2021-47261

2024-05-2115:15:14

416baaa9-dc9f-4396-8d5f-8c081fb06d67

web.nvd.nist.gov

linux kernel

vulnerability

ib/mlx5

initializing

cq fragments buffer

fix

6.7 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

15.5%

JSON

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

IB/mlx5: Fix initializing CQ fragments buffer

The function init_cq_frag_buf() can be called to initialize the current CQ
fragments buffer cq->buf, or the temporary cq->resize_buf that is filled
during CQ resize operation.

However, the offending commit started to use function get_cqe() for
getting the CQEs, the issue with this change is that get_cqe() always
returns CQEs from cq->buf, which leads us to initialize the wrong buffer,
and in case of enlarging the CQ we try to access elements beyond the size
of the current cq->buf and eventually hit a kernel panic.

[exception RIP: init_cq_frag_buf+103]
[ffff9f799ddcbcd8] mlx5_ib_resize_cq at ffffffffc0835d60 [mlx5_ib]
[ffff9f799ddcbdb0] ib_resize_cq at ffffffffc05270df [ib_core]
[ffff9f799ddcbdc0] llt_rdma_setup_qp at ffffffffc0a6a712 [llt]
[ffff9f799ddcbe10] llt_rdma_cc_event_action at ffffffffc0a6b411 [llt]
[ffff9f799ddcbe98] llt_rdma_client_conn_thread at ffffffffc0a6bb75 [llt]
[ffff9f799ddcbec8] kthread at ffffffffa66c5da1
[ffff9f799ddcbf50] ret_from_fork_nospec_begin at ffffffffa6d95ddd

Fix it by getting the needed CQE by calling mlx5_frag_buf_get_wqe() that
takes the correct source buffer as a parameter.

Affected configurations

Vulners

Node

linuxlinux_kernelRange4.17–4.19.195

linuxlinux_kernelRange4.20.0–5.4.126

linuxlinux_kernelRange5.5.0–5.10.44

linuxlinux_kernelRange5.11.0–5.12.11

linuxlinux_kernelRange5.13.0≥

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/infiniband/hw/mlx5/cq.c"
    ],
    "versions": [
      {
        "version": "388ca8be0037",
        "lessThan": "1ec2dcd680c7",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "388ca8be0037",
        "lessThan": "e3ecd9c09fcc",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "388ca8be0037",
        "lessThan": "91f7fdc4cc10",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "388ca8be0037",
        "lessThan": "3e670c54eda2",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "388ca8be0037",
        "lessThan": "2ba0aa2feebd",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/infiniband/hw/mlx5/cq.c"
    ],
    "versions": [
      {
        "version": "4.17",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "4.17",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.19.195",
        "lessThanOrEqual": "4.19.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.4.126",
        "lessThanOrEqual": "5.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.44",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.12.11",
        "lessThanOrEqual": "5.12.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.13",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]