CVE-2022-49290

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.

Gravité et risque d'exploitation

CVE-2022-49290 obtient un score CVSS de 7.8/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.26 %, ce qui la place devant 16.4 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions 3212d6248faf0efce6b7a718e198feecce0eea05, 4f3193e08602462a806e8f53212e79c60a6f7488, <=5.17.*, 4.4.233, 5.18, <4a2d4496e15ea5bb5c8e83b94ca8ca7fb045e7d3, 0, 5.4.56, <4.14.274, <12e407a8ef17623823fd0c066fbd7f103953d28d, 6a01afcf8468d3ca2bd8bbb27503f60dcf643b20, <4.9.309, <5.8, 5.17.1, 5.7.13, <=4.9.*, <5d3ff9542a40ce034416bca03864709540a36016, <5.4.188, 4.14.274, 12e9cb1e7c93413112260991d094cfda712fdc97, <=4.14.*, <615716af8644813355e014314a0bc1e961250f5a, <582d8c60c0c053684f7138875e8150d5749ffc17, <46bb87d40683337757a2f902fcd4244b32bb4e86, 4.9.233, 37bccfa89559a70c044b5ccde3c916a91388e14a, 4.9.309, <=5.10.*, 5.15.32, <273ebddc5fda2967492cb0b6cdd7d81cfb821b76, 86e7d4cd2ed5f4b0188afce8199faffcf1ae7c7e, <4.5, 4.19.237, <c1d9c3628ef0a0ca197595d0f9e01cd3b5dda186, 5.4.188, <=5.4.*, 4.19.137, <=4.19.*, 5.10.109, <=5.16.*, 4.14.192, <=*, <=5.15.*, <4.19.237, 5.8, 5.16.18, <3bbd0000d012f92aec423b224784fbf0f7bf40f8, 3f15e3e62c80e180282f0cbc5559264e11c328b7) est présent sur votre parc.
• Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
• À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
• Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.

Références

• https://git.kernel.org/stable/c/615716af8644813355e014314a0bc1e961250f5a
• https://git.kernel.org/stable/c/c1d9c3628ef0a0ca197595d0f9e01cd3b5dda186
• https://git.kernel.org/stable/c/273ebddc5fda2967492cb0b6cdd7d81cfb821b76
• https://git.kernel.org/stable/c/3bbd0000d012f92aec423b224784fbf0f7bf40f8
• https://git.kernel.org/stable/c/5d3ff9542a40ce034416bca03864709540a36016
• https://git.kernel.org/stable/c/12e407a8ef17623823fd0c066fbd7f103953d28d
• https://git.kernel.org/stable/c/582d8c60c0c053684f7138875e8150d5749ffc17
• https://git.kernel.org/stable/c/46bb87d40683337757a2f902fcd4244b32bb4e86
• https://git.kernel.org/stable/c/4a2d4496e15ea5bb5c8e83b94ca8ca7fb045e7d3