CVE-2025-38397
MediumIn 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---
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected versions
Linux kernel versions
6.15
and later are affected. Fixed in
6.15.6,
6.16
and their respective stable series.
References
The following references provide additional information about CVE-2025-38397 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/a432383e6cd86d9fda00a6073ed35c1067a836d6
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PatchKernel patch commithttps://git.kernel.org/stable/c/d6811074203b13f715ce2480ac64c5b1c773f2a5
Frequently asked questions
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What is CVE-2025-38397?
CVE-2025-38397 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 6.15 onward and has been patched in 6.15.6 and 6.16. CVE-2025-38397 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2025-38397?
CVE-2025-38397 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2025-38397?
Yes — CVE-2025-38397 has been patched. Fixed versions include 6.15.6 and 6.16. If you are running Linux kernel 6.15 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2025-38397 actively exploited?
No — CVE-2025-38397 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.