In the Linux kernel, the following vulnerability has been resolved: ipv4: ip_tunnel: Fix suspicious RCU usage warning in ip_tunnel_find() The per-netns IP tunnel hash table is protected by the RTNL mutex and ip_tunnel_find() is only called from the control path where the mutex is taken. Add a lockdep expression to hlist_for_each_entry_rcu() in ip_tunnel_find() in order to validate that the mutex is held and to silence the suspicious RCU usage warning [1]. [1] WARNING: suspicious RCU usage 6.12.0-rc3-custom-gd95d9a31aceb #139 Not tainted ----------------------------- net/ipv4/ip_tunnel.c:221 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by ip/362: #0: ffffffff86fc7cb0 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x377/0xf60 stack backtrace: CPU: 12 UID: 0 PID: 362 Comm: ip Not tainted 6.12.0-rc3-custom-gd95d9a31aceb #139 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: <TASK> dump_stack_lvl+0xba/0x110 lockdep_rcu_suspicious.cold+0x4f/0xd6 ip_tunnel_find+0x435/0x4d0 ip_tunnel_newlink+0x517/0x7a0 ipgre_newlink+0x14c/0x170 __rtnl_newlink+0x1173/0x19c0 rtnl_newlink+0x6c/0xa0 rtnetlink_rcv_msg+0x3cc/0xf60 netlink_rcv_skb+0x171/0x450 netlink_unicast+0x539/0x7f0 netlink_sendmsg+0x8c1/0xd80 ____sys_sendmsg+0x8f9/0xc20 ___sys_sendmsg+0x197/0x1e0 __sys_sendmsg+0x122/0x1f0 do_syscall_64+0xbb/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f
| Métrique | Valeur | Interprétation |
|---|---|---|
|
AV (Vecteur d'Attaque)
Attack Vector
|
Local (L)
|
Exploit nécessite un accès local au système |
|
AC (Complexité d'Attaque)
Attack Complexity
|
Low (L)
|
Peu de conditions requises pour exploiter |
|
PR (Privilèges Requis)
Privileges Required
|
Low (L)
|
Authentifié avec compte utilisateur basique |
|
UI (Interaction Utilisateur)
User Interaction
|
None (N)
|
Aucune interaction utilisateur nécessaire |
|
S (Périmètre)
Scope
|
Unchanged (U)
|
Impact reste dans le périmètre du composant compromis |
|
C (Impact Confidentialité)
Confidentiality Impact
|
None (N)
|
Aucune divulgation d'informations |
|
I (Impact Intégrité)
Integrity Impact
|
None (N)
|
Aucune modification de données possible |
|
A (Impact Disponibilité)
Availability Impact
|
High (H)
|
Interruption totale du service possible |
ipv4: ip_tunnel: Fix suspicious RCU usage warning in ip_tunnel_find()