CVE-2025-21805 [Medium] | Security Vulnerability in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: RDMA/rtrs: Add missing deinit() call A warning is triggered when repeatedly connecting and disconnecting the rnbd: list_add corruption. prev->next should be next (ffff88800b13e480), but was ffff88801ecd1338. (prev=ffff88801ecd1340). WARNING: CPU: 1 PID: 36562 at lib/list_debug.c:32 __list_add_valid_or_report+0x7f/0xa0 Workqueue: ib_cm cm_work_handler [ib_cm] RIP: 0010:__list_add_valid_or_report+0x7f/0xa0 ? __list_add_valid_or_report+0x7f/0xa0 ib_register_event_handler+0x65/0x93 [ib_core] rtrs_srv_ib_dev_init+0x29/0x30 [rtrs_server] rtrs_ib_dev_find_or_add+0x124/0x1d0 [rtrs_core] __alloc_path+0x46c/0x680 [rtrs_server] ? rtrs_rdma_connect+0xa6/0x2d0 [rtrs_server] ? rcu_is_watching+0xd/0x40 ? __mutex_lock+0x312/0xcf0 ? get_or_create_srv+0xad/0x310 [rtrs_server] ? rtrs_rdma_connect+0xa6/0x2d0 [rtrs_server] rtrs_rdma_connect+0x23c/0x2d0 [rtrs_server] ? __lock_release+0x1b1/0x2d0 cma_cm_event_handler+0x4a/0x1a0 [rdma_cm] cma_ib_req_handler+0x3a0/0x7e0 [rdma_cm] cm_process_work+0x28/0x1a0 [ib_cm] ? _raw_spin_unlock_irq+0x2f/0x50 cm_req_handler+0x618/0xa60 [ib_cm] cm_work_handler+0x71/0x520 [ib_cm] Commit 667db86bcbe8 ("RDMA/rtrs: Register ib event handler") introduced a new element .deinit but never used it at all. Fix it by invoking the `deinit()` to appropriately unregister the IB event handler.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.04%	0.17%	+0.13%
2	2025-02-28	—	0.04%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.04%

0.17%

+0.13%

2025-02-28

—

0.04%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.5	3.1	MEDIUM	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	3.6	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

5.5

3.1

MEDIUM

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

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

3.6

[email protected]

OS Trackers for CVE-2025-21805

vendor	priority	summary	link
`debian`	unimportant	CVE-2025-21805 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2025-21805
`redhat`	—	—	https://access.redhat.com/security/cve/CVE-2025-21805
`suse`	medium	—	https://www.suse.com/security/cve/CVE-2025-21805/
`ubuntu`	medium	CVE-2025-21805 medium priority: Ubuntu including 128 source packages (linux, linux-allwinner-5.19, …), 1024 status rows across 8 suites (bionic, focal, jammy, noble, oracular, trusty, upstream, xenial): DNE 702, ignored 146, not-affected 114, released 62.	https://ubuntu.com/security/CVE-2025-21805

Affected software / configurations for CVE-2025-21805

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 6.12, < 6.12.13	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.13, < 6.13.2	cpe:2.3:o:linux:linux_kernel::::::::

References for CVE-2025-21805

URL	Tags
https://git.kernel.org/stable/c/1af2c769032b6b334cd2a867d7d8c7cbbc527b2d	Patch
https://git.kernel.org/stable/c/5a79cc9bc961fafe90787f86e8f53ba6fad8d63b	Patch
https://git.kernel.org/stable/c/81468c4058a62e84e475433b83b3edc613294f5e	Patch

URL

CVE-2025-21805 | RDMA/rtrs: Add missing deinit() call

Exploit prediction scoring system (EPSS) score for CVE-2025-21805

Common vulnerability scoring system (CVSS) metrics for CVE-2025-21805

Weakness enumeration for CVE-2025-21805

OS Trackers for CVE-2025-21805

Affected software / configurations for CVE-2025-21805

References for CVE-2025-21805