7.8
HIGH
CVE-2024-56640
Linux SMC Use-After-Free Vulnerability
Description

In the Linux kernel, the following vulnerability has been resolved: net/smc: fix LGR and link use-after-free issue We encountered a LGR/link use-after-free issue, which manifested as the LGR/link refcnt reaching 0 early and entering the clear process, making resource access unsafe. refcount_t: addition on 0; use-after-free. WARNING: CPU: 14 PID: 107447 at lib/refcount.c:25 refcount_warn_saturate+0x9c/0x140 Workqueue: events smc_lgr_terminate_work [smc] Call trace: refcount_warn_saturate+0x9c/0x140 __smc_lgr_terminate.part.45+0x2a8/0x370 [smc] smc_lgr_terminate_work+0x28/0x30 [smc] process_one_work+0x1b8/0x420 worker_thread+0x158/0x510 kthread+0x114/0x118 or refcount_t: underflow; use-after-free. WARNING: CPU: 6 PID: 93140 at lib/refcount.c:28 refcount_warn_saturate+0xf0/0x140 Workqueue: smc_hs_wq smc_listen_work [smc] Call trace: refcount_warn_saturate+0xf0/0x140 smcr_link_put+0x1cc/0x1d8 [smc] smc_conn_free+0x110/0x1b0 [smc] smc_conn_abort+0x50/0x60 [smc] smc_listen_find_device+0x75c/0x790 [smc] smc_listen_work+0x368/0x8a0 [smc] process_one_work+0x1b8/0x420 worker_thread+0x158/0x510 kthread+0x114/0x118 It is caused by repeated release of LGR/link refcnt. One suspect is that smc_conn_free() is called repeatedly because some smc_conn_free() from server listening path are not protected by sock lock. e.g. Calls under socklock | smc_listen_work ------------------------------------------------------- lock_sock(sk) | smc_conn_abort smc_conn_free | \- smc_conn_free \- smcr_link_put | \- smcr_link_put (duplicated) release_sock(sk) So here add sock lock protection in smc_listen_work() path, making it exclusive with other connection operations.

INFO

Published Date :

Dec. 27, 2024, 3:15 p.m.

Last Modified :

Feb. 11, 2025, 4:15 p.m.

Source :

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

Remotely Exploitable :

No

Impact Score :

5.9

Exploitability Score :

1.8
Public PoC/Exploit Available at Github

CVE-2024-56640 has a 1 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

Affected Products

The following products are affected by CVE-2024-56640 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

None

Updated: 2 days, 10 hours ago
4 stars 1 fork 1 watcher
Born at : April 16, 2025, 1:43 p.m. This repo has been linked 280 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2024-56640 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2024-56640 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Feb. 11, 2025

    Action Type Old Value New Value
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-416
  • Initial Analysis by [email protected]

    Jan. 14, 2025

    Action Type Old Value New Value
    Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    Added CWE NIST CWE-416
    Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.18 up to (excluding) 5.15.174 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.120 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.66 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.5 *cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:*
    Changed Reference Type https://git.kernel.org/stable/c/0cf598548a6c36d90681d53c6b77d52363f2f295 No Types Assigned https://git.kernel.org/stable/c/0cf598548a6c36d90681d53c6b77d52363f2f295 Patch
    Changed Reference Type https://git.kernel.org/stable/c/2c7f14ed9c19ec0f149479d1c2842ec1f9bf76d7 No Types Assigned https://git.kernel.org/stable/c/2c7f14ed9c19ec0f149479d1c2842ec1f9bf76d7 Patch
    Changed Reference Type https://git.kernel.org/stable/c/673d606683ac70bc074ca6676b938bff18635226 No Types Assigned https://git.kernel.org/stable/c/673d606683ac70bc074ca6676b938bff18635226 Patch
    Changed Reference Type https://git.kernel.org/stable/c/6f0ae06a234a78ae137064f2c89135ac078a00eb No Types Assigned https://git.kernel.org/stable/c/6f0ae06a234a78ae137064f2c89135ac078a00eb Patch
    Changed Reference Type https://git.kernel.org/stable/c/f502a88fdd415647a1f2dc45fac71b9c522a052b No Types Assigned https://git.kernel.org/stable/c/f502a88fdd415647a1f2dc45fac71b9c522a052b Patch
  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Dec. 27, 2024

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: net/smc: fix LGR and link use-after-free issue We encountered a LGR/link use-after-free issue, which manifested as the LGR/link refcnt reaching 0 early and entering the clear process, making resource access unsafe. refcount_t: addition on 0; use-after-free. WARNING: CPU: 14 PID: 107447 at lib/refcount.c:25 refcount_warn_saturate+0x9c/0x140 Workqueue: events smc_lgr_terminate_work [smc] Call trace: refcount_warn_saturate+0x9c/0x140 __smc_lgr_terminate.part.45+0x2a8/0x370 [smc] smc_lgr_terminate_work+0x28/0x30 [smc] process_one_work+0x1b8/0x420 worker_thread+0x158/0x510 kthread+0x114/0x118 or refcount_t: underflow; use-after-free. WARNING: CPU: 6 PID: 93140 at lib/refcount.c:28 refcount_warn_saturate+0xf0/0x140 Workqueue: smc_hs_wq smc_listen_work [smc] Call trace: refcount_warn_saturate+0xf0/0x140 smcr_link_put+0x1cc/0x1d8 [smc] smc_conn_free+0x110/0x1b0 [smc] smc_conn_abort+0x50/0x60 [smc] smc_listen_find_device+0x75c/0x790 [smc] smc_listen_work+0x368/0x8a0 [smc] process_one_work+0x1b8/0x420 worker_thread+0x158/0x510 kthread+0x114/0x118 It is caused by repeated release of LGR/link refcnt. One suspect is that smc_conn_free() is called repeatedly because some smc_conn_free() from server listening path are not protected by sock lock. e.g. Calls under socklock | smc_listen_work ------------------------------------------------------- lock_sock(sk) | smc_conn_abort smc_conn_free | \- smc_conn_free \- smcr_link_put | \- smcr_link_put (duplicated) release_sock(sk) So here add sock lock protection in smc_listen_work() path, making it exclusive with other connection operations.
    Added Reference https://git.kernel.org/stable/c/0cf598548a6c36d90681d53c6b77d52363f2f295
    Added Reference https://git.kernel.org/stable/c/2c7f14ed9c19ec0f149479d1c2842ec1f9bf76d7
    Added Reference https://git.kernel.org/stable/c/673d606683ac70bc074ca6676b938bff18635226
    Added Reference https://git.kernel.org/stable/c/6f0ae06a234a78ae137064f2c89135ac078a00eb
    Added Reference https://git.kernel.org/stable/c/f502a88fdd415647a1f2dc45fac71b9c522a052b
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2024-56640 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2024-56640 weaknesses.

CVSS31 - Vulnerability Scoring System
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Latest DB Update: Apr. 26, 2025 15:14