Linux Kernel up to 6.16-rc2 atm atmtcp_c_send memory leak

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4.9$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.16-rc2. It has been classified as problematic. Affected is the function atmtcp_c_send of the component atm. Performing a manipulation results in an unknown weakness. This vulnerability is reported as CVE-2025-38185. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.16-rc2. It has been classified as problematic. This affects the function atmtcp_c_send of the component atm. CWE is classifying the issue as CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: atm: atmtcp: Free invalid length skb in atmtcp_c_send(). syzbot reported the splat below. [0] vcc_sendmsg() copies data passed from userspace to skb and passes it to vcc->dev->ops->send(). atmtcp_c_send() accesses skb->data as struct atmtcp_hdr after checking if skb->len is 0, but it's not enough. Also, when skb->len == 0, skb and sk (vcc) were leaked because dev_kfree_skb() is not called and sk_wmem_alloc adjustment is missing to revert atm_account_tx() in vcc_sendmsg(), which is expected to be done in atm_pop_raw(). Let's properly free skb with an invalid length in atmtcp_c_send(). [0]: BUG: KMSAN: uninit-value in atmtcp_c_send+0x255/0xed0 drivers/atm/atmtcp.c:294 atmtcp_c_send+0x255/0xed0 drivers/atm/atmtcp.c:294 vcc_sendmsg+0xd7c/0xff0 net/atm/common.c:644 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x330/0x3d0 net/socket.c:727 ____sys_sendmsg+0x7e0/0xd80 net/socket.c:2566 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2620 __sys_sendmsg net/socket.c:2652 [inline] __do_sys_sendmsg net/socket.c:2657 [inline] __se_sys_sendmsg net/socket.c:2655 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2655 x64_sys_call+0x32fb/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was created at: slab_post_alloc_hook mm/slub.c:4154 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_node_noprof+0x818/0xf00 mm/slub.c:4249 kmalloc_reserve+0x13c/0x4b0 net/core/skbuff.c:579 __alloc_skb+0x347/0x7d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1336 [inline] vcc_sendmsg+0xb40/0xff0 net/atm/common.c:628 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x330/0x3d0 net/socket.c:727 ____sys_sendmsg+0x7e0/0xd80 net/socket.c:2566 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2620 __sys_sendmsg net/socket.c:2652 [inline] __do_sys_sendmsg net/socket.c:2657 [inline] __se_sys_sendmsg net/socket.c:2655 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2655 x64_sys_call+0x32fb/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f CPU: 1 UID: 0 PID: 5798 Comm: syz-executor192 Not tainted 6.16.0-rc1-syzkaller-00010-g2c4a1f3fe03e #0 PREEMPT(undef) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-38185 since 04/16/2025. The exploitability is told to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 249177 (Debian dsa-5973 : affs-modules-6.1.0-37-4kc-malta-di - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.4.295, 5.10.239, 5.15.186, 6.1.142, 6.6.95, 6.12.35, 6.15.4 or 6.16-rc3 eliminates this vulnerability. Applying the patch c19c0943424b412a84fdf178e6c71fe5480e4f0f/a4b0fd8c25a7583f8564af6cc910418fb8954e89/1b0ad18704913c92a3ad53748fbc0f219a75b876/ca00f0e6d733ecd9150716d1fd0138d26e674706/3261c017a7c5d2815c6a388c5a3280d1fba0e8db/e996507f59610e5752b8702537f13f551e7a2c96/c9260c837de1d2b454960a4a2e44a81272fbcd22/2f370ae1fb6317985f3497b1bb80d457508ca2f7 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 (249177), EUVD (EUVD-2025-20071) and CERT Bund (WID-SEC-2025-1465). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

  • 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: 5.0
VulDB Meta Temp Score: 4.9

VulDB Base Score: 4.6
VulDB Temp Score: 4.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

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

Exploitinginfo

Class: Memory leak
CWE: CWE-401 / CWE-404
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: 249177
Nessus Name: Debian dsa-5973 : affs-modules-6.1.0-37-4kc-malta-di - security update

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.4.295/5.10.239/5.15.186/6.1.142/6.6.95/6.12.35/6.15.4/6.16-rc3
Patch: c19c0943424b412a84fdf178e6c71fe5480e4f0f/a4b0fd8c25a7583f8564af6cc910418fb8954e89/1b0ad18704913c92a3ad53748fbc0f219a75b876/ca00f0e6d733ecd9150716d1fd0138d26e674706/3261c017a7c5d2815c6a388c5a3280d1fba0e8db/e996507f59610e5752b8702537f13f551e7a2c96/c9260c837de1d2b454960a4a2e44a81272fbcd22/2f370ae1fb6317985f3497b1bb80d457508ca2f7

Timelineinfo

04/16/2025 CVE reserved
07/04/2025 +79 days Advisory disclosed
07/04/2025 +0 days VulDB entry created
12/19/2025 +168 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-38185 (🔒)
GCVE (CVE): GCVE-0-2025-38185
GCVE (VulDB): GCVE-100-314907
EUVD: 🔒
CERT Bund: WID-SEC-2025-1465 - Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service

Entryinfo

Created: 07/04/2025 16:17
Updated: 12/19/2025 03:25
Changes: 07/04/2025 16:17 (57), 07/04/2025 21:07 (1), 07/20/2025 16:13 (7), 08/13/2025 22:05 (2), 08/25/2025 14:20 (1), 09/02/2025 11:25 (1), 09/10/2025 19:53 (1), 09/20/2025 23:07 (1), 11/02/2025 23:48 (1), 12/08/2025 05:43 (1), 12/19/2025 03:25 (14)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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