i2c: core: fix debugfs UAF on adapter removal
Published Sep 16, 2026
No CVSS score
EPSS 0.21%
Description
i2c_del_adapter() frees the adapter's debugfs directory before it unregisters the adapter device, but the new_device sysfs attribute stays writable until device_del(). A write racing with removal still reaches i2c_device_probe(), which passes the freed adap->debugfs to debugfs_create_dir() as the new client's parent:
BUG: KASAN: slab-use-after-free in lookup_noperm_common+0x407/0x430 Read of size 4 at addr ffff88803ef87810 by task syz.0.61/6090 lookup_noperm_common+0x407/0x430 simple_start_creating+0x9c/0x110 debugfs_start_creating+0xdb/0x1a0 debugfs_create_dir+0x24/0x350 i2c_device_probe+0x814/0xbf0
It's technically possible to create a client after i2c_deregister_clients has run. That client will never be unregistered and make wait_for_completion hang.
Close the window by removing the new_device attribute at the start of i2c_del_adapter(). device_remove_file() will drain any clients left.
Affected products
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- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
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- Version
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- Version 5.15.168StatusaffectedConstraints<5.15.221
- Version 6.1.113StatusaffectedConstraints<6.1.188
- Version 6.6.55StatusaffectedConstraints<6.6.157
- Version
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- Version 6.8StatusaffectedConstraints-
- Version 0StatusunaffectedConstraints<6.8
- Version 5.15.221StatusunaffectedConstraints<=5.15.*
- Version 6.1.188StatusunaffectedConstraints<=6.1.*
- Version 6.12.110StatusunaffectedConstraints<=6.12.*
- Version 6.18.51StatusunaffectedConstraints<=6.18.*
- Version 6.6.157StatusunaffectedConstraints<=6.6.*
- Version 7.2.5StatusunaffectedConstraints<=7.2.*
- Version 7.3-rc1StatusunaffectedConstraints<=*
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
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| Linux | Linux | unaffected |
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| Linux | Linux | unaffected |
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| Linux | Linux | affected |
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No data.
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
No CWE recorded.
References (7)
- https://git.kernel.org/stable/c/112b3d48084c820bbccf41d9783fd122e3ac4cb0
- https://git.kernel.org/stable/c/1f1bcd4eca6caa3e4258d9a31925112539406eb6
- https://git.kernel.org/stable/c/552836be2d95c688eede6371f85532abe1a71232
- https://git.kernel.org/stable/c/643fb872aa04342d27dbef52b2b3cf3fe71b2c7b
- https://git.kernel.org/stable/c/b15b548d52b43ba8ac4652bc2c7244a8dd1e9622
- https://git.kernel.org/stable/c/dc33a9762538b3250ed6b5644a4d44c748be33a6
- https://git.kernel.org/stable/c/f9094ace03e0a532cc6505d2e97b61ae738da4ed
Change history (0)
No recorded changes yet.