Linux KernelOperating system · Linux
CVE-2025-71079
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn the Linux kernel, the following vulnerability has been resolved: net: nfc: fix deadlock between nfc_unregister_device and rfkill_fop_write A deadlock can occur between nfc_unregister_device() and rfkill_fop_write() due to lock ordering inversion between device_lock and rfkill_global_mutex. The problematic lock order is: Thread A (rfkill_fop_write): rfkill_fop_write() mutex_lock(&rfkill_global_mutex) rfkill_set_block() nfc_rfkill_set_block() nfc_dev_down() device_lock(&dev->dev) <- waits for device_lock Thread B (nfc_unregister_device): nfc_unregister_device() device_lock(&dev->dev) rfkill_unregister() mutex_lock(&rfkill_global_mutex) <- waits for rfkill_global_mutex This creates a classic ABBA deadlock scenario. Fix this by moving rfkill_unregister() and rfkill_destroy() outside the device_lock critical section. Store the rfkill pointer in a local variable before releasing the lock, then call rfkill_unregister() after releasing device_lock. This change is safe because rfkill_fop_write() holds rfkill_global_mutex while calling the rfkill callbacks, and rfkill_unregister() also acquires rfkill_global_mutex before cleanup. Therefore, rfkill_unregister() will wait for any ongoing callback to complete before proceeding, and device_del() is only called after rfkill_unregister() returns, preventing any use-after-free. The similar lock ordering in nfc_register_device() (device_lock -> rfkill_global_mutex via rfkill_register) is safe because during registration the device is not yet in rfkill_list, so no concurrent rfkill operations can occur on this device.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisShared resources are accessed without correct locking, so concurrent operations interleave into inconsistent — and sometimes exploitable — states, or deadlock the service outright. These bugs are subtle and timing-dependent. The fix is correct, consistent locking or atomic operations around every shared resource.
General guidance for the improper locking class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Linux KernelOperating system
>= 4.4.293, < 4.5>= 4.9.291, < 4.10>= 4.14.256, < 4.15>= 4.19.218, < 4.20>= 5.4.162, < 5.5>= 5.10.82, < 5.10.248>= 5.15.5, < 5.15.198>= 5.16.1, < 6.1.160>= 6.2, < 6.6.120>= 6.7, < 6.12.64>= 6.13, < 6.18.4= 5.16CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped4.54.104.15
Upgrade to kernel 4.5 or later (for 4.4.x), 4.10 or later (for 4.9.x), 4.15 or later (for 4.14.x), or 4.20 or later (for 4.19.x)
- Identify the current running kernel version using `uname -r`
- Determine which kernel branch your version belongs to (4.4.x, 4.9.x, 4.14.x, or 4.19.x)
- Upgrade to a fixed kernel release: for 4.4.x branch upgrade to >= 4.5, for 4.9.x upgrade to >= 4.10, for 4.14.x upgrade to >= 4.15, for 4.19.x upgrade to >= 4.20
- Apply the vendor patch from commit 1ab526d97a57e44d26fadcc0e9adeb9c0c0182f5 if upgrading is not possible: modify nfc_unregister_device() to move rfkill_unregister() and rfkill_destroy() calls outside the device_lock section by storing the rfkill pointer in a local variable before releasing the lock, then calling rfkill_unregister() after releasing device_lock
- Reboot into the new kernel to apply the fix
Generated from the published advisory — verify against the referenced sources before acting.
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Free · runs locallyCheck whether your project pulls in CVE-2025-71079 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-71079 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
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