i2c: core: Fix double-free of fwnode in i2c_unregister_device()
Before commit df6d7277e552 ("i2c: core: Do not dereference fwnode in struct
device"), i2c_unregister_device() only called fwnode_handle_put() on
of_node-s in the form of calling of_node_put(client->dev.of_node).
But after this commit the i2c_client's fwnode now unconditionally gets
fwnode_handle_put() on it.
When the i2c_client has no primary (ACPI / OF) fwnode but it does have
a software fwnode, the software-node will be the primary node and
fwnode_handle_put() will put() it.
But for the software fwnode device_remove_software_node() will also put()
it leading to a double free:
[ 82.665598] ------------[ cut here ]------------
[ 82.665609] refcount_t: underflow; use-after-free.
[ 82.665808] WARNING: CPU: 3 PID: 1502 at lib/refcount.c:28 refcount_warn_saturate+0xba/0x11
...
[ 82.666830] RIP: 0010:refcount_warn_saturate+0xba/0x110
...
[ 82.666962] <TASK>
[ 82.666971] i2c_unregister_device+0x60/0x90
Fix this by not calling fwnode_handle_put() when the primary fwnode is
a software-node.
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No vendor fix or workaround currently provided.
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Tracking
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| Source | ID | Title |
|---|---|---|
EUVD |
EUVD-2025-26787 | In the Linux kernel, the following vulnerability has been resolved: i2c: core: Fix double-free of fwnode in i2c_unregister_device() Before commit df6d7277e552 ("i2c: core: Do not dereference fwnode in struct device"), i2c_unregister_device() only called fwnode_handle_put() on of_node-s in the form of calling of_node_put(client->dev.of_node). But after this commit the i2c_client's fwnode now unconditionally gets fwnode_handle_put() on it. When the i2c_client has no primary (ACPI / OF) fwnode but it does have a software fwnode, the software-node will be the primary node and fwnode_handle_put() will put() it. But for the software fwnode device_remove_software_node() will also put() it leading to a double free: [ 82.665598] ------------[ cut here ]------------ [ 82.665609] refcount_t: underflow; use-after-free. [ 82.665808] WARNING: CPU: 3 PID: 1502 at lib/refcount.c:28 refcount_warn_saturate+0xba/0x11 ... [ 82.666830] RIP: 0010:refcount_warn_saturate+0xba/0x110 ... [ 82.666962] <TASK> [ 82.666971] i2c_unregister_device+0x60/0x90 Fix this by not calling fwnode_handle_put() when the primary fwnode is a software-node. |
Tue, 25 Nov 2025 22:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-415 | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Metrics |
cvssV3_1
|
cvssV3_1
|
Fri, 05 Sep 2025 14:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Vendors & Products |
Linux
Linux linux Kernel |
Fri, 05 Sep 2025 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Thu, 04 Sep 2025 15:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: i2c: core: Fix double-free of fwnode in i2c_unregister_device() Before commit df6d7277e552 ("i2c: core: Do not dereference fwnode in struct device"), i2c_unregister_device() only called fwnode_handle_put() on of_node-s in the form of calling of_node_put(client->dev.of_node). But after this commit the i2c_client's fwnode now unconditionally gets fwnode_handle_put() on it. When the i2c_client has no primary (ACPI / OF) fwnode but it does have a software fwnode, the software-node will be the primary node and fwnode_handle_put() will put() it. But for the software fwnode device_remove_software_node() will also put() it leading to a double free: [ 82.665598] ------------[ cut here ]------------ [ 82.665609] refcount_t: underflow; use-after-free. [ 82.665808] WARNING: CPU: 3 PID: 1502 at lib/refcount.c:28 refcount_warn_saturate+0xba/0x11 ... [ 82.666830] RIP: 0010:refcount_warn_saturate+0xba/0x110 ... [ 82.666962] <TASK> [ 82.666971] i2c_unregister_device+0x60/0x90 Fix this by not calling fwnode_handle_put() when the primary fwnode is a software-node. | |
| Title | i2c: core: Fix double-free of fwnode in i2c_unregister_device() | |
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-11T21:32:56.493Z
Reserved: 2025-04-16T04:51:24.031Z
Link: CVE-2025-38682
No data.
Status : Analyzed
Published: 2025-09-04T16:15:35.910
Modified: 2025-11-25T22:06:13.123
Link: CVE-2025-38682
OpenCVE Enrichment
Updated: 2025-09-05T14:02:52Z
EUVD