Linux KernelOperating system · Linux

CVE-2024-56641

MEDIUM · 5.5 CVSS v3.1 Published 2024-12-27
Fix available
A fix is available. Upgrade to 6.6.66 / 6.12.5 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In the Linux kernel, the following vulnerability has been resolved: net/smc: initialize close_work early to avoid warning We encountered a warning that close_work was canceled before initialization. WARNING: CPU: 7 PID: 111103 at kernel/workqueue.c:3047 __flush_work+0x19e/0x1b0 Workqueue: events smc_lgr_terminate_work [smc] RIP: 0010:__flush_work+0x19e/0x1b0 Call Trace: ? __wake_up_common+0x7a/0x190 ? work_busy+0x80/0x80 __cancel_work_timer+0xe3/0x160 smc_close_cancel_work+0x1a/0x70 [smc] smc_close_active_abort+0x207/0x360 [smc] __smc_lgr_terminate.part.38+0xc8/0x180 [smc] process_one_work+0x19e/0x340 worker_thread+0x30/0x370 ? process_one_work+0x340/0x340 kthread+0x117/0x130 ? __kthread_cancel_work+0x50/0x50 ret_from_fork+0x22/0x30 This is because when smc_close_cancel_work is triggered, e.g. the RDMA driver is rmmod and the LGR is terminated, the conn->close_work is flushed before initialization, resulting in WARN_ON(!work->func). __smc_lgr_terminate | smc_connect_{rdma|ism} ------------------------------------------------------------- | smc_conn_create | \- smc_lgr_register_conn for conn in lgr->conns_all | \- smc_conn_kill | \- smc_close_active_abort | \- smc_close_cancel_work | \- cancel_work_sync | \- __flush_work | (close_work) | | smc_close_init | \- INIT_WORK(&close_work) So fix this by initializing close_work before establishing the connection.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis

A detailed technical summary for this CVE is being prepared.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 4.12, < 6.6.66>= 6.7, < 6.12.5= 6.13

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 6.6.66 / 6.12.5 or later
Fixed in 6.6.666.12.5
Vendor patch git.kernel.org →
Recommended fix High confidence

Linux Kernel 6.6.66+, 6.12.5+, or 6.13.1+ (depending on which version branch you are on)

  1. 1. Identify the current running Linux kernel version using 'uname -r' or 'cat /proc/version'
  2. 2. Determine the appropriate fixed kernel version based on your current version: if >= 4.12 and < 6.6.66, upgrade to 6.6.66 or later; if >= 6.7 and < 6.12.5, upgrade to 6.12.5 or later; if 6.13, upgrade to 6.13.1 or later
  3. 3. Update the kernel package using your distribution's package manager (e.g., apt-get update && apt-get install linux-image-<version>, yum update kernel, dnf update kernel, or similar)
  4. 4. Reboot the system to load the new kernel
  5. 5. Verify the new kernel is running with 'uname -r' and confirm the version includes the fix
Caveat Kernel upgrades carry standard upgrade risks including potential driver incompatibilities; test in non-production environment first

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,600. Get the upgrade done

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-56641 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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