CVE-2025-38397

Published Jul 25, 2025

Last updated 7 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: nvme-multipath: fix suspicious RCU usage warning When I run the NVME over TCP test in virtme-ng, I get the following "suspicious RCU usage" warning in nvme_mpath_add_sysfs_link(): ''' [ 5.024557][ T44] nvmet: Created nvm controller 1 for subsystem nqn.2025-06.org.nvmexpress.mptcp for NQN nqn.2014-08.org.nvmexpress:uuid:f7f6b5e0-ff97-4894-98ac-c85309e0bc77. [ 5.027401][ T183] nvme nvme0: creating 2 I/O queues. [ 5.029017][ T183] nvme nvme0: mapped 2/0/0 default/read/poll queues. [ 5.032587][ T183] nvme nvme0: new ctrl: NQN "nqn.2025-06.org.nvmexpress.mptcp", addr 127.0.0.1:4420, hostnqn: nqn.2014-08.org.nvmexpress:uuid:f7f6b5e0-ff97-4894-98ac-c85309e0bc77 [ 5.042214][ T25] [ 5.042440][ T25] ============================= [ 5.042579][ T25] WARNING: suspicious RCU usage [ 5.042705][ T25] 6.16.0-rc3+ #23 Not tainted [ 5.042812][ T25] ----------------------------- [ 5.042934][ T25] drivers/nvme/host/multipath.c:1203 RCU-list traversed in non-reader section!! [ 5.043111][ T25] [ 5.043111][ T25] other info that might help us debug this: [ 5.043111][ T25] [ 5.043341][ T25] [ 5.043341][ T25] rcu_scheduler_active = 2, debug_locks = 1 [ 5.043502][ T25] 3 locks held by kworker/u9:0/25: [ 5.043615][ T25] #0: ffff888008730948 ((wq_completion)async){+.+.}-{0:0}, at: process_one_work+0x7ed/0x1350 [ 5.043830][ T25] #1: ffffc900001afd40 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work+0xcf3/0x1350 [ 5.044084][ T25] #2: ffff888013ee0020 (&head->srcu){.+.+}-{0:0}, at: nvme_mpath_add_sysfs_link.part.0+0xb4/0x3a0 [ 5.044300][ T25] [ 5.044300][ T25] stack backtrace: [ 5.044439][ T25] CPU: 0 UID: 0 PID: 25 Comm: kworker/u9:0 Not tainted 6.16.0-rc3+ #23 PREEMPT(full) [ 5.044441][ T25] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 5.044442][ T25] Workqueue: async async_run_entry_fn [ 5.044445][ T25] Call Trace: [ 5.044446][ T25] <TASK> [ 5.044449][ T25] dump_stack_lvl+0x6f/0xb0 [ 5.044453][ T25] lockdep_rcu_suspicious.cold+0x4f/0xb1 [ 5.044457][ T25] nvme_mpath_add_sysfs_link.part.0+0x2fb/0x3a0 [ 5.044459][ T25] ? queue_work_on+0x90/0xf0 [ 5.044461][ T25] ? lockdep_hardirqs_on+0x78/0x110 [ 5.044466][ T25] nvme_mpath_set_live+0x1e9/0x4f0 [ 5.044470][ T25] nvme_mpath_add_disk+0x240/0x2f0 [ 5.044472][ T25] ? __pfx_nvme_mpath_add_disk+0x10/0x10 [ 5.044475][ T25] ? add_disk_fwnode+0x361/0x580 [ 5.044480][ T25] nvme_alloc_ns+0x81c/0x17c0 [ 5.044483][ T25] ? kasan_quarantine_put+0x104/0x240 [ 5.044487][ T25] ? __pfx_nvme_alloc_ns+0x10/0x10 [ 5.044495][ T25] ? __pfx_nvme_find_get_ns+0x10/0x10 [ 5.044496][ T25] ? rcu_read_lock_any_held+0x45/0xa0 [ 5.044498][ T25] ? validate_chain+0x232/0x4f0 [ 5.044503][ T25] nvme_scan_ns+0x4c8/0x810 [ 5.044506][ T25] ? __pfx_nvme_scan_ns+0x10/0x10 [ 5.044508][ T25] ? find_held_lock+0x2b/0x80 [ 5.044512][ T25] ? ktime_get+0x16d/0x220 [ 5.044517][ T25] ? kvm_clock_get_cycles+0x18/0x30 [ 5.044520][ T25] ? __pfx_nvme_scan_ns_async+0x10/0x10 [ 5.044522][ T25] async_run_entry_fn+0x97/0x560 [ 5.044523][ T25] ? rcu_is_watching+0x12/0xc0 [ 5.044526][ T25] process_one_work+0xd3c/0x1350 [ 5.044532][ T25] ? __pfx_process_one_work+0x10/0x10 [ 5.044536][ T25] ? assign_work+0x16c/0x240 [ 5.044539][ T25] worker_thread+0x4da/0xd50 [ 5.044545][ T25] ? __pfx_worker_thread+0x10/0x10 [ 5.044546][ T25] kthread+0x356/0x5c0 [ 5.044548][ T25] ? __pfx_kthread+0x10/0x10 [ 5.044549][ T25] ? ret_from_fork+0x1b/0x2e0 [ 5.044552][ T25] ? __lock_release.isra.0+0x5d/0x180 [ 5.044553][ T25] ? ret_from_fork+0x1b/0x2e0 [ 5.044555][ T25] ? rcu_is_watching+0x12/0xc0 [ 5.044557][ T25] ? __pfx_kthread+0x10/0x10 [ 5.04 ---truncated---
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
NVD-CWE-noinfo

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: coresight: tmc-etr: Fix race condition between sysfs and perf mode When trying to run perf and sysfs mode simultaneously, the WARN_ON() in tmc_etr_enable_hw() is triggered sometimes: WARNING: CPU: 42 PID: 3911571 at drivers/hwtracing/coresight/coresight-tmc-etr.c:1060 tmc_etr_enable_hw+0xc0/0xd8 [coresight_tmc] [..snip..] Call trace: tmc_etr_enable_hw+0xc0/0xd8 [coresight_tmc] (P) tmc_enable_etr_sink+0x11c/0x250 [coresight_tmc] (L) tmc_enable_etr_sink+0x11c/0x250 [coresight_tmc] coresight_enable_path+0x1c8/0x218 [coresight] coresight_enable_sysfs+0xa4/0x228 [coresight] enable_source_store+0x58/0xa8 [coresight] dev_attr_store+0x20/0x40 sysfs_kf_write+0x4c/0x68 kernfs_fop_write_iter+0x120/0x1b8 vfs_write+0x2c8/0x388 ksys_write+0x74/0x108 __arm64_sys_write+0x24/0x38 el0_svc_common.constprop.0+0x64/0x148 do_el0_svc+0x24/0x38 el0_svc+0x3c/0x130 el0t_64_sync_handler+0xc8/0xd0 el0t_64_sync+0x1ac/0x1b0 ---[ end trace 0000000000000000 ]--- Since the enablement of sysfs mode is separeted into two critical regions, one for sysfs buffer allocation and another for hardware enablement, it's possible to race with the perf mode. Fix this by double check whether the perf mode's been used before enabling the hardware in sysfs mode. mode: [sysfs mode] [perf mode] tmc_etr_get_sysfs_buffer() spin_lock(&drvdata->spinlock) [sysfs buffer allocation] spin_unlock(&drvdata->spinlock) spin_lock(&drvdata->spinlock) tmc_etr_enable_hw() drvdata->etr_buf = etr_perf->etr_buf spin_unlock(&drvdata->spinlock) spin_lock(&drvdata->spinlock) tmc_etr_enable_hw() WARN_ON(drvdata->etr_buf) // WARN sicne etr_buf initialized at the perf side spin_unlock(&drvdata->spinlock) With this fix, we retain the check for CS_MODE_PERF in get_etr_sysfs_buf. This ensures we verify whether the perf mode's already running before we actually allocate the buffer. Then we can save the time of allocating/freeing the sysfs buffer if race with the perf mode.CVE-2026-46272