Linux Kernel up to 3627605de498639a3c586c8684d12c89cba11073 bpf skb_send_sock reference count

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CTI Interest Score
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6.2$0-$5k2.86

Summaryinfo

A vulnerability described as critical has been identified in Linux Kernel up to 3627605de498639a3c586c8684d12c89cba11073. Affected by this vulnerability is the function skb_send_sock of the component bpf. Such manipulation leads to reference count. This vulnerability is uniquely identified as CVE-2025-38154. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 3627605de498639a3c586c8684d12c89cba11073. Affected by this issue is the function skb_send_sock of the component bpf. The manipulation with an unknown input leads to a reference count vulnerability. Using CWE to declare the problem leads to CWE-911. The product uses a reference count to manage a resource, but it does not update or incorrectly updates the reference count. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Avoid using sk_socket after free when sending The sk->sk_socket is not locked or referenced in backlog thread, and during the call to skb_send_sock(), there is a race condition with the release of sk_socket. All types of sockets(tcp/udp/unix/vsock) will be affected. Race conditions: ''' CPU0 CPU1 backlog::skb_send_sock sendmsg_unlocked sock_sendmsg sock_sendmsg_nosec close(fd): ... ops->release() -> sock_map_close() sk_socket->ops = NULL free(socket) sock->ops->sendmsg ^ panic here ''' The ref of psock become 0 after sock_map_close() executed. ''' void sock_map_close() { ... if (likely(psock)) { ... // !! here we remove psock and the ref of psock become 0 sock_map_remove_links(sk, psock) psock = sk_psock_get(sk); if (unlikely(!psock)) goto no_psock; <=== Control jumps here via goto ... cancel_delayed_work_sync(&psock->work); <=== not executed sk_psock_put(sk, psock); ... } ''' Based on the fact that we already wait for the workqueue to finish in sock_map_close() if psock is held, we simply increase the psock reference count to avoid race conditions. With this patch, if the backlog thread is running, sock_map_close() will wait for the backlog thread to complete and cancel all pending work. If no backlog running, any pending work that hasn't started by then will fail when invoked by sk_psock_get(), as the psock reference count have been zeroed, and sk_psock_drop() will cancel all jobs via cancel_delayed_work_sync(). In summary, we require synchronization to coordinate the backlog thread and close() thread. The panic I catched: ''' Workqueue: events sk_psock_backlog RIP: 0010:sock_sendmsg+0x21d/0x440 RAX: 0000000000000000 RBX: ffffc9000521fad8 RCX: 0000000000000001 ... Call Trace: <TASK> ? die_addr+0x40/0xa0 ? exc_general_protection+0x14c/0x230 ? asm_exc_general_protection+0x26/0x30 ? sock_sendmsg+0x21d/0x440 ? sock_sendmsg+0x3e0/0x440 ? __pfx_sock_sendmsg+0x10/0x10 __skb_send_sock+0x543/0xb70 sk_psock_backlog+0x247/0xb80 ... '''

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2025-38154 since 04/16/2025. The exploitation is known to be difficult. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 243500 (Amazon Linux 2023 : bpftool, kernel, kernel-devel (ALAS2023-2025-1111)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.15.186, 6.1.142, 6.6.94, 6.12.34, 6.15.3 or 6.16-rc1 eliminates this vulnerability. Applying the patch 4edb40b05cb6a261775abfd8046804ca139a5546/b19cbf0b9a91f5a0d93fbcd761ff71c48ab40ed9/4c6fa65ab2aec7df94809478c8d28ef38676a1b7/15c0250dae3b48a398447d2b364603821ed4ed90/7c0a16f6ea2b1c82a03bccd5d1bdb4a7bbd4d987/8259eb0e06d8f64c700f5fbdb28a5c18e10de291 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (243500), EUVD (EUVD-2025-19790) and CERT Bund (WID-SEC-2025-1452). Once again VulDB remains the best source for vulnerability data.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • IBM QRadar SIEM
  • SUSE openSUSE
  • RESF Rocky Linux
  • Dell Avamar
  • Open Source Linux Kernel
  • Dell NetWorker
  • Dell Secure Connect Gateway

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.2

VulDB Base Score: 4.8
VulDB Temp Score: 4.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Reference count
CWE: CWE-911 / CWE-664
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 243500
Nessus Name: Amazon Linux 2023 : bpftool, kernel, kernel-devel (ALAS2023-2025-1111)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.15.186/6.1.142/6.6.94/6.12.34/6.15.3/6.16-rc1
Patch: 4edb40b05cb6a261775abfd8046804ca139a5546/b19cbf0b9a91f5a0d93fbcd761ff71c48ab40ed9/4c6fa65ab2aec7df94809478c8d28ef38676a1b7/15c0250dae3b48a398447d2b364603821ed4ed90/7c0a16f6ea2b1c82a03bccd5d1bdb4a7bbd4d987/8259eb0e06d8f64c700f5fbdb28a5c18e10de291

Timelineinfo

04/16/2025 CVE reserved
07/03/2025 +78 days Advisory disclosed
07/03/2025 +0 days VulDB entry created
04/18/2026 +289 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-38154 (🔒)
GCVE (CVE): GCVE-0-2025-38154
GCVE (VulDB): GCVE-100-314732
EUVD: 🔒
CERT Bund: WID-SEC-2025-1452 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 07/03/2025 12:12
Updated: 04/18/2026 09:37
Changes: 07/03/2025 12:12 (59), 07/03/2025 12:48 (1), 08/05/2025 12:15 (2), 08/23/2025 20:18 (7), 09/21/2025 20:11 (1), 11/09/2025 16:15 (1), 12/06/2025 17:48 (1), 12/19/2025 01:39 (13), 04/18/2026 09:37 (1)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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