Rapid7 Vulnerability & Exploit Database

Huawei EulerOS: CVE-2021-47391: kernel security update

Free InsightVM Trial No Credit Card Necessary
2024 Attack Intel Report Latest research by Rapid7 Labs
Back to Search

Huawei EulerOS: CVE-2021-47391: kernel security update

Severity
4
CVSS
(AV:L/AC:M/Au:N/C:P/I:P/A:P)
Published
05/21/2024
Created
11/06/2024
Added
11/05/2024
Modified
11/05/2024

Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/cma: Ensure rdma_addr_cancel() happens before issuing more requests The FSM can run in a circle allowing rdma_resolve_ip() to be called twice on the same id_priv. While this cannot happen without going through the work, it violates the invariant that the same address resolution background request cannot be active twice. CPU 1 CPU 2 rdma_resolve_addr(): RDMA_CM_IDLE -> RDMA_CM_ADDR_QUERY rdma_resolve_ip(addr_handler) #1 process_one_req(): for #1 addr_handler(): RDMA_CM_ADDR_QUERY -> RDMA_CM_ADDR_BOUND mutex_unlock(&id_priv->handler_mutex); [.. handler still running ..] rdma_resolve_addr(): RDMA_CM_ADDR_BOUND -> RDMA_CM_ADDR_QUERY rdma_resolve_ip(addr_handler) !! two requests are now on the req_list rdma_destroy_id(): destroy_id_handler_unlock(): _destroy_id(): cma_cancel_operation(): rdma_addr_cancel() // process_one_req() self removes it spin_lock_bh(&lock); cancel_delayed_work(&req->work); if (!list_empty(&req->list)) == true ! rdma_addr_cancel() returns after process_on_req #1 is done kfree(id_priv) process_one_req(): for #2 addr_handler(): mutex_lock(&id_priv->handler_mutex); !! Use after free on id_priv rdma_addr_cancel() expects there to be one req on the list and only cancels the first one. The self-removal behavior of the work only happens after the handler has returned. This yields a situations where the req_list can have two reqs for the same "handle" but rdma_addr_cancel() only cancels the first one. The second req remains active beyond rdma_destroy_id() and will use-after-free id_priv once it inevitably triggers. Fix this by remembering if the id_priv has called rdma_resolve_ip() and always cancel before calling it again. This ensures the req_list never gets more than one item in it and doesn't cost anything in the normal flow that never uses this strange error path.

Solution(s)

  • huawei-euleros-2_0_sp12-upgrade-bpftool
  • huawei-euleros-2_0_sp12-upgrade-kernel
  • huawei-euleros-2_0_sp12-upgrade-kernel-abi-stablelists
  • huawei-euleros-2_0_sp12-upgrade-kernel-tools
  • huawei-euleros-2_0_sp12-upgrade-kernel-tools-libs
  • huawei-euleros-2_0_sp12-upgrade-python3-perf

insightVM

Advanced vulnerability management analytics and reporting.
Key Features
  • Lightweight Endpoint Agent
  • Live Dashboards
  • Real Risk Prioritization
  • IT-Integrated Remediation Projects
  • Cloud, Virtual, and Container Assessment
  • Integrated Threat Feeds
  • Easy-to-Use RESTful API
  • Automation-Assisted Patching
  • Automated Containment
Free InsightVM Trial View All Features

With Rapid7 live dashboards, I have a clear view of all the assets on my network, which ones can be exploited, and what I need to do in order to reduce the risk in my environment in real-time. No other tool gives us that kind of value and insight.

– Scott Cheney, Manager of Information Security, Sierra View Medical Center

;