CVE-2025-39932Critical· 9.8▾ Midnight

smb: client: let smbd_destroy() call disable_work_sync(&info->post_send_credits_work)

In the Linux kernel, the following vulnerability has been resolved: smb: client: let smbd_destroy() call disable_work_sync(&info->post_send_credits_work) In smbd_destroy() we may destroy the memory so we better wait until post_send_cre…

▾ Midnight zone — Critical, or high with PoC / in-the-wild

Depth score54/ 100 · Moderate

impact 53.9 · likelihood 0.1 · exploitation 0

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Proof of concept

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Published

Oct 4, 2025

Updated

Oct 15, 2026

CVSS

9.8

Vendor

Linux

Product

Linux

CWE

—

Depth score

54 · Moderate

EPSS

0.29% · p22

Platforms

—

Source

CVEORG

Vector

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

CISA SSVC

decided 2026-10-15

Exploitation: none
Automatable: yes
Technical impact: total

Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake. The CVSS score shown above comes from the assigning CNA record, not NVD.

EPSS history

Exploit-prediction probability, daily snapshots since Oct 15.

0.3% → 0.3%

Timeline

Disclosure to exploitation, from the record and what we observed since indexing it.

4 events · 392 days

Oct 4, 2025Published
Disclosed via CVEORG
Oct 15, 2026Record revised
Last analysed / modified upstream
Oct 15, 2026EPSS first tracked
0.3%
Oct 31, 2026EPSS peak
0.3% → 0.3%

Linux #cve.org

Affected

Linux >= f198186aa9bbd60fae7a2061f4feec614d880299 < 6ae90a2baf923e85eb037b636aa641250bf4220f
Linux >= f198186aa9bbd60fae7a2061f4feec614d880299 < 3fabb1236f2e3ad78d531be0a4ad9f4a4ccdda87
Linux >= f198186aa9bbd60fae7a2061f4feec614d880299 < d9dcbbcf9145b68aa85c40947311a6907277e097
Linux 4.16

Full technical detail▾

Overview

In the Linux kernel, the following vulnerability has been resolved:

smb: client: let smbd_destroy() call disable_work_sync(&info->post_send_credits_work)

In smbd_destroy() we may destroy the memory so we better wait until post_send_credits_work is no longer pending and will never be started again.

I actually just hit the case using rxe:

WARNING: CPU: 0 PID: 138 at drivers/infiniband/sw/rxe/rxe_verbs.c:1032 rxe_post_recv+0x1ee/0x480 [rdma_rxe] ... [ 5305.686979] [ T138] smbd_post_recv+0x445/0xc10 [cifs] [ 5305.687135] [ T138] ? srso_alias_return_thunk+0x5/0xfbef5 [ 5305.687149] [ T138] ? __kasan_check_write+0x14/0x30 [ 5305.687185] [ T138] ? __pfx_smbd_post_recv+0x10/0x10 [cifs] [ 5305.687329] [ T138] ? __pfx__raw_spin_lock_irqsave+0x10/0x10 [ 5305.687356] [ T138] ? srso_alias_return_thunk+0x5/0xfbef5 [ 5305.687368] [ T138] ? srso_alias_return_thunk+0x5/0xfbef5 [ 5305.687378] [ T138] ? _raw_spin_unlock_irqrestore+0x11/0x60 [ 5305.687389] [ T138] ? srso_alias_return_thunk+0x5/0xfbef5 [ 5305.687399] [ T138] ? get_receive_buffer+0x168/0x210 [cifs] [ 5305.687555] [ T138] smbd_post_send_credits+0x382/0x4b0 [cifs] [ 5305.687701] [ T138] ? __pfx_smbd_post_send_credits+0x10/0x10 [cifs] [ 5305.687855] [ T138] ? __pfx___schedule+0x10/0x10 [ 5305.687865] [ T138] ? __pfx__raw_spin_lock_irq+0x10/0x10 [ 5305.687875] [ T138] ? queue_delayed_work_on+0x8e/0xa0 [ 5305.687889] [ T138] process_one_work+0x629/0xf80 [ 5305.687908] [ T138] ? srso_alias_return_thunk+0x5/0xfbef5 [ 5305.687917] [ T138] ? __kasan_check_write+0x14/0x30 [ 5305.687933] [ T138] worker_thread+0x87f/0x1570 ...

It means rxe_post_recv was called after rdma_destroy_qp(). This happened because put_receive_buffer() was triggered by ib_drain_qp() and called: queue_work(info->workqueue, &info->post_send_credits_work);

Affected

Linux >= f198186aa9bbd60fae7a2061f4feec614d880299 < 6ae90a2baf923e85eb037b636aa641250bf4220f
Linux >= f198186aa9bbd60fae7a2061f4feec614d880299 < 3fabb1236f2e3ad78d531be0a4ad9f4a4ccdda87
Linux >= f198186aa9bbd60fae7a2061f4feec614d880299 < d9dcbbcf9145b68aa85c40947311a6907277e097
Linux 4.16

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

References

Related vulnerabilities

Connected by shared product, vendor, weakness, or advisory.

#cve.org

smb: client: let smbd_destroy() call disable_work_sync(&info->post_send_credits_work)

▾ Midnight zone — Critical, or high with PoC / in-the-wild

Depth score54/ 100 · Moderate

impact 53.9 · likelihood 0.1 · exploitation 0

Overview

In the Linux kernel, the following vulnerability has been resolved:

smb: client: let smbd_destroy() call disable_work_sync(&info->post_send_credits_work)

In smbd_destroy() we may destroy the memory so we better wait until post_send_credits_work is no longer pending and will never be started again.

I actually just hit the case using rxe: