CVE-2022-49290·Kernel vulnerability
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.
- Severity
- high
- Software
- Kernel
- Fixed in
- 5.17.1
- Published
- 2025-02-26
Affected versions
From: 5.17
Until: 5.17.1
Fixed in: 5.17.1
How to fix this CVE
Update your Linux kernel to version 5.17.1 or later to resolve a double-free memory corruption vulnerability in the mesh networking stack. This issue occurs when rejoining a mesh network after a previous mesh leave operation, potentially causing kernel panics. Prioritize this patch for systems using mesh networking, particularly those running custom mesh applications rather than standard wpa_supplicant configurations.
sudo dnf update kernel kernel-develDefensia detects this vulnerability
How to check if you are affected
- Check your kernel version with: uname -r (vulnerable if output shows 5.17.0 or 5.17.1-rc versions)
- Verify mesh networking is enabled: grep -i mesh /boot/config-$(uname -r) | grep CONFIG_MAC80211_MESH
- Search system logs for mesh-related crashes: sudo journalctl -b | grep -i 'mesh\|ieee80211' | grep -i 'error\|panic\|double free'
- Confirm patched kernel is running after update: uname -r (should show 5.17.1 or higher with matching date of update)
FAQ
What is CVE-2022-49290?
This vulnerability is a double-free memory corruption bug in Linux kernel's mac80211 mesh networking implementation that triggers when a mesh network is left and then rejoined, potentially causing kernel panics and system instability.
Is CVE-2022-49290 being actively exploited?
No, this vulnerability is not listed in CISA's Known Exploited Vulnerabilities catalog and no public exploits are available. However, it can be triggered locally through mesh network reconfiguration.
What versions of Kernel are affected by CVE-2022-49290?
Linux kernel versions 5.17.0 through 5.17.1-rc are vulnerable. The fix was included starting from the stable 5.17.1 release.
How do I check if my server is vulnerable to CVE-2022-49290?
Run 'uname -r' and check if output shows version 5.17.0 or 5.17.1-rc; also verify mesh support with 'grep CONFIG_MAC80211_MESH /boot/config-$(uname -r)' to confirm the vulnerable component is compiled in.
Does Defensia detect CVE-2022-49290?
Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2022-49290 will appear in your dashboard with remediation steps.
Related Kernel CVEs
References
- https://git.kernel.org/stable/c/12e407a8ef17623823fd0c066fbd7f103953d28d
- https://git.kernel.org/stable/c/273ebddc5fda2967492cb0b6cdd7d81cfb821b76
- https://git.kernel.org/stable/c/3bbd0000d012f92aec423b224784fbf0f7bf40f8
- https://git.kernel.org/stable/c/46bb87d40683337757a2f902fcd4244b32bb4e86
- https://git.kernel.org/stable/c/4a2d4496e15ea5bb5c8e83b94ca8ca7fb045e7d3
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