Bug 1220623 (CVE-2021-46979)

Summary:	VUL-0: CVE-2021-46979: kernel: iio: core: fix ioctl handlers removal
Product:	[Novell Products] SUSE Security Incidents	Reporter:	SMASH SMASH <smash_bz>
Component:	Incidents	Assignee:	Kernel Bugs <kernel-bugs>
Status:	RESOLVED FIXED	QA Contact:	Security Team bot <security-team>
Severity:	Normal
Priority:	P5 - None	CC:	gianluca.gabrielli
Version:	unspecified
Target Milestone:	---
Hardware:	Other
OS:	Other
URL:	https://smash.suse.de/issue/395428/
Whiteboard:
Found By:	Security Response Team	Services Priority:
Business Priority:		Blocker:	---
Marketing QA Status:	---	IT Deployment:	---

Description SMASH SMASH 2024-02-29 09:01:16 UTC

In the Linux kernel, the following vulnerability has been resolved:

iio: core: fix ioctl handlers removal

Currently ioctl handlers are removed twice. For the first time during
iio_device_unregister() then later on inside
iio_device_unregister_eventset() and iio_buffers_free_sysfs_and_mask().
Double free leads to kernel panic.

Fix this by not touching ioctl handlers list directly but rather
letting code responsible for registration call the matching cleanup
routine itself.

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-46979
https://git.kernel.org/stable/c/ab6c935ba3a04317632f3b8b68675bdbaf395303
https://www.cve.org/CVERecord?id=CVE-2021-46979
https://git.kernel.org/stable/c/11e1cae5da4096552f7c091476cbadbc0d1817da
https://git.kernel.org/stable/c/901f84de0e16bde10a72d7eb2f2eb73fcde8fa1a