CVE-2025-21805

CriticalCVSS 9.8

Published: 27/02/2025(UTC)Updated: 30/07/2026(UTC)Translated: 30/07/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.37%

30th percentile - higher than 30% of all known CVEs

Summary

In the Linux kernel's RDMA/rtrs driver, the deinit() function is missing during disconnection, so the IB event handler registration is not undone. This leads to list corruption when repeatedly connecting and disconnecting.

Risk Assessment

Repeatedly connecting and disconnecting rnbd connections can cause system crashes or unpredictable behavior due to corruption of kernel internal data structures.

Recommendation

Install the Linux kernel update that fixes CVE-2025-21805 by adding the deinit() call in the appropriate place.

Original NVD description (English source)

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.