vulnerability

Huawei EulerOS: CVE-2021-47261: kernel security update

Severity
7
CVSS
(AV:L/AC:L/Au:S/C:C/I:C/A:C)
Published
May 21, 2024
Added
Jan 21, 2025
Modified
Aug 13, 2025

Description

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.

Solutions

huawei-euleros-2_0_sp8-upgrade-bpftoolhuawei-euleros-2_0_sp8-upgrade-kernelhuawei-euleros-2_0_sp8-upgrade-kernel-develhuawei-euleros-2_0_sp8-upgrade-kernel-headershuawei-euleros-2_0_sp8-upgrade-kernel-toolshuawei-euleros-2_0_sp8-upgrade-kernel-tools-libshuawei-euleros-2_0_sp8-upgrade-perfhuawei-euleros-2_0_sp8-upgrade-python-perfhuawei-euleros-2_0_sp8-upgrade-python3-perf
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