In the Linux kernel, the following vulnerability has been resolved: mac80211: fix potential double free on mesh join While commit 6a01afcf8468 ("mac80211: mesh: Free ie data when leaving mesh") fixed a memory leak on mesh leave / teardown it introduced a potential memory corruption caused by a double free when rejoining the mesh: ieee80211_leave_mesh() -> kfree(sdata->u.mesh.ie); ... ieee80211_join_mesh() -> copy_mesh_setup() -> old_ie = ifmsh->ie; -> kfree(old_ie); This double free / kernel panics can be reproduced by using wpa_supplicant with an encrypted mesh (if set up without encryption via "iw" then ifmsh->ie is always NULL, which avoids this issue). And then calling: $ iw dev mesh0 mesh leave $ iw dev mesh0 mesh join my-mesh Note that typically these commands are not used / working when using wpa_supplicant. And it seems that wpa_supplicant or wpa_cli are going through a NETDEV_DOWN/NETDEV_UP cycle between a mesh leave and mesh join where the NETDEV_UP resets the mesh.ie to NULL via a memcpy of default_mesh_setup in cfg80211_netdev_notifier_call, which then avoids the memory corruption, too. The issue was first observed in an application which was not using wpa_supplicant but "Senf" instead, which implements its own calls to nl80211. Fixing the issue by removing the kfree()'ing of the mesh IE in the mesh join function and leaving it solely up to the mesh leave to free the mesh IE.
History

Mon, 14 Apr 2025 20:30:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-415
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}


Thu, 27 Feb 2025 13:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Wed, 26 Feb 2025 02:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: mac80211: fix potential double free on mesh join While commit 6a01afcf8468 ("mac80211: mesh: Free ie data when leaving mesh") fixed a memory leak on mesh leave / teardown it introduced a potential memory corruption caused by a double free when rejoining the mesh: ieee80211_leave_mesh() -> kfree(sdata->u.mesh.ie); ... ieee80211_join_mesh() -> copy_mesh_setup() -> old_ie = ifmsh->ie; -> kfree(old_ie); This double free / kernel panics can be reproduced by using wpa_supplicant with an encrypted mesh (if set up without encryption via "iw" then ifmsh->ie is always NULL, which avoids this issue). And then calling: $ iw dev mesh0 mesh leave $ iw dev mesh0 mesh join my-mesh Note that typically these commands are not used / working when using wpa_supplicant. And it seems that wpa_supplicant or wpa_cli are going through a NETDEV_DOWN/NETDEV_UP cycle between a mesh leave and mesh join where the NETDEV_UP resets the mesh.ie to NULL via a memcpy of default_mesh_setup in cfg80211_netdev_notifier_call, which then avoids the memory corruption, too. The issue was first observed in an application which was not using wpa_supplicant but "Senf" instead, which implements its own calls to nl80211. Fixing the issue by removing the kfree()'ing of the mesh IE in the mesh join function and leaving it solely up to the mesh leave to free the mesh IE.
Title mac80211: fix potential double free on mesh join
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-02-26T01:56:27.500Z

Reserved: 2025-02-26T01:49:39.302Z

Link: CVE-2022-49290

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2025-02-26T07:01:05.853

Modified: 2025-04-14T20:07:47.107

Link: CVE-2022-49290

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-02-26T00:00:00Z

Links: CVE-2022-49290 - Bugzilla