CVE intelligence and bounded remediation

CVE-2021-47392 — Linux Linux Kernel security vulnerability

Medium CVSS 5.5

In the Linux kernel, the following vulnerability has been resolved: RDMA/cma: Fix listener leak in rdma_cma_listen_on_all() failure If cma_listen_on_all() fails it leaves the per-device ID still on the listen_list but the state is not set to RDMA_CM_ADDR_BOUND. When the cmid is eventually destroyed cma_cancel_listens() is not called due to the wrong state, however the per-device IDs are still holding the refcount preventing the ID from being destroyed, thus deadlocking: task:rping state:D stack: 0 pid:19605 ppid: 47036 flags:0x00000084 Call Trace: __schedule+0x29a/0x780 ? free_unref_page_commit+0x9b/0x110 schedule+0x3c/0xa0 schedule_timeout+0x215/0x2b0 ? __flush_work+0x19e/0x1e0 wait_for_completion+0x8d/0xf0 _destroy_id+0x144/0x210 [rdma_cm] ucma_close_id+0x2b/0x40 [rdma_ucm] __destroy_id+0x93/0x2c0 [rdma_ucm] ? __xa_erase+0x4a/0xa0 ucma_destroy_id+0x9a/0x120 [rdma_ucm] ucma_write+0xb8/0x130 [rdma_ucm] vfs_write+0xb4/0x250 ksys_write+0xb5/0xd0 ? syscall_trace_enter.isra.19+0x123/0x190 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Ensure that cma_listen_on_all() atomically unwinds its action under the lock during error.

Severity
Medium
CVSS
5.5 (3.1)
Published
2024-05-21
CISA KEV
Not currently listed
Ecosystem
linux/kernel
Weaknesses
CWE-401

Affected products

  • linux / linux_kernel
  • linux / linux_kernel / 5.15

Showing 2 representative product identities from 5 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Resource exhaustion and denial of service

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
  • Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
  • Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.

Remediate safely

  • Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
  • Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
  • Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.

Authoritative sources

Complete CVE record and remediation plan

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