Use After Free Affecting kernel-default-vdso package, versions <6.12.0-160000.6.1


Severity

Recommended
0.0
medium
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.04% (10th percentile)

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  • Snyk IDSNYK-SLES1600-KERNELDEFAULTVDSO-13931034
  • published13 Nov 2025
  • disclosed6 Nov 2025

Introduced: 6 Nov 2025

NewCVE-2025-38209  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade SLES:16.0.0 kernel-default-vdso to version 6.12.0-160000.6.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-default-vdso package and not the kernel-default-vdso package as distributed by SLES. See How to fix? for SLES:16.0.0 relevant fixed versions and status.

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

nvme-tcp: remove tag set when second admin queue config fails

Commit 104d0e2f6222 ("nvme-fabrics: reset admin connection for secure concatenation") modified nvme_tcp_setup_ctrl() to call nvme_tcp_configure_admin_queue() twice. The first call prepares for DH-CHAP negotitation, and the second call is required for secure concatenation. However, this change triggered BUG KASAN slab-use-after- free in blk_mq_queue_tag_busy_iter(). This BUG can be recreated by repeating the blktests test case nvme/063 a few times [1].

When the BUG happens, nvme_tcp_create_ctrl() fails in the call chain below:

nvme_tcp_create_ctrl() nvme_tcp_alloc_ctrl() new=true ... Alloc nvme_tcp_ctrl and admin_tag_set nvme_tcp_setup_ctrl() new=true nvme_tcp_configure_admin_queue() new=true ... Succeed nvme_alloc_admin_tag_set() ... Alloc the tag set for admin_tag_set nvme_stop_keep_alive() nvme_tcp_teardown_admin_queue() remove=false nvme_tcp_configure_admin_queue() new=false nvme_tcp_alloc_admin_queue() ... Fail, but do not call nvme_remove_admin_tag_set() nvme_uninit_ctrl() nvme_put_ctrl() ... Free up the nvme_tcp_ctrl and admin_tag_set

The first call of nvme_tcp_configure_admin_queue() succeeds with new=true argument. The second call fails with new=false argument. This second call does not call nvme_remove_admin_tag_set() on failure, due to the new=false argument. Then the admin tag set is not removed. However, nvme_tcp_create_ctrl() assumes that nvme_tcp_setup_ctrl() would call nvme_remove_admin_tag_set(). Then it frees up struct nvme_tcp_ctrl which has admin_tag_set field. Later on, the timeout handler accesses the admin_tag_set field and causes the BUG KASAN slab-use-after-free.

To not leave the admin tag set, call nvme_remove_admin_tag_set() when the second nvme_tcp_configure_admin_queue() call fails. Do not return from nvme_tcp_setup_ctrl() on failure. Instead, jump to "destroy_admin" go-to label to call nvme_tcp_teardown_admin_queue() which calls nvme_remove_admin_tag_set().

CVSS Base Scores

version 3.1