CVE-2021-47195

spi: fix use-after-free of the add_lock mutex

MEDIUM
5.5
CVSS Score
Published: April 10, 2024 at 06:56 PM UTC
Updated: June 17, 2026 at 04:16 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: spi: fix use-after-free of the add_lock mutex Commit 6098475d4cb4 ("spi: Fix deadlock when adding SPI controllers on SPI buses") introduced a per-controller mutex. But mutex_unlock() of said lock is called after the controller is already freed: spi_unregister_controller(ctlr) -> put_device(&ctlr->dev) -> spi_controller_release(dev) -> mutex_unlock(&ctrl->add_lock) Move the put_device() after the mutex_unlock().

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≥ 5.14.155.14.15 ≤ v < 5.155.15 ≤ v < 5.15.55.15 ≤ v < 5.165.15.0 < v < 5.15.55.14.155.156098475d4cb48d821bdf453c61118c56e26294f0722ef19a161ce3fffb3d1b01ce2301c306639bddaa3f3d7bef59583f2d3234173105a27ff61ef8fec8dce228db6f81dbc897a018dfc5c418e917cf64
Vendor states this is fixed in 11eab327a2a8bd36c38afbff920ae1bd45588dd4 (fixed)
Vendor states this is fixed in 37330f37f6666c7739a44b2b6b95b047ccdbed2d (fixed)
Vendor states this is fixed in 54c2c96eafcfd242e52e932ab54ace4784efe1dd (fixed)
Vendor states this is fixed in 6c53b45c71b4920b5e62f0ea8079a1da382b9434 (fixed)
Vendor states this is fixed in 5.15 (unaffected)
Vendor states this is fixed in 5.15.5 (unaffected)
Vendor states this is fixed in 5.16 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (4)

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-416

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