In the Linux kernel, the following vulnerability has been resolved:
ovpn: avoid putting unrelated P2P peer on socket release
ovpn_peer_release_p2p() is called when an OVPN UDP socket is being
destroyed. It checks the currently published P2P peer and releases it only
if that peer still uses the socket being destroyed.
A peer replacement can publish a new peer before the old UDP socket is
destroyed. When the old socket destruction path runs afterwards,
ovpn_peer_release_p2p() observes the new peer through ovpn->peer. Since the
new peer uses a different socket, the function takes the socket mismatch
branch.
That branch still calls ovpn_peer_put(peer). At this point, however, peer
is the currently published replacement peer, not the peer associated with
the socket being destroyed. Dropping its reference can free it while
ovpn->peer still points to it, leading to later use-after-free accesses
from the peer and socket cleanup paths.
KASAN reports this as a slab-use-after-free on the kmalloc-1k ovpn_peer
object. In the reproducer, the object is allocated from ovpn_peer_new() via
ovpn_nl_peer_new_doit(), and freed through ovpn_peer_release_rcu() from RCU
callback processing. Observed access sites include ovpn_peer_remove(),
ovpn_socket_release(), ovpn_nl_peer_del_notify(), and unlock_ovpn().
Fix this by returning from the socket mismatch branch without putting the
peer.
Metrics
Affected Vendors & Products
References
History
Mon, 10 Aug 2026 16:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-416 |
Mon, 10 Aug 2026 12:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: ovpn: avoid putting unrelated P2P peer on socket release ovpn_peer_release_p2p() is called when an OVPN UDP socket is being destroyed. It checks the currently published P2P peer and releases it only if that peer still uses the socket being destroyed. A peer replacement can publish a new peer before the old UDP socket is destroyed. When the old socket destruction path runs afterwards, ovpn_peer_release_p2p() observes the new peer through ovpn->peer. Since the new peer uses a different socket, the function takes the socket mismatch branch. That branch still calls ovpn_peer_put(peer). At this point, however, peer is the currently published replacement peer, not the peer associated with the socket being destroyed. Dropping its reference can free it while ovpn->peer still points to it, leading to later use-after-free accesses from the peer and socket cleanup paths. KASAN reports this as a slab-use-after-free on the kmalloc-1k ovpn_peer object. In the reproducer, the object is allocated from ovpn_peer_new() via ovpn_nl_peer_new_doit(), and freed through ovpn_peer_release_rcu() from RCU callback processing. Observed access sites include ovpn_peer_remove(), ovpn_socket_release(), ovpn_nl_peer_del_notify(), and unlock_ovpn(). Fix this by returning from the socket mismatch branch without putting the peer. | |
| Title | ovpn: avoid putting unrelated P2P peer on socket release | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-10T12:03:18.852Z
Reserved: 2026-07-30T09:28:09.384Z
Link: CVE-2026-68342
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OpenCVE Enrichment
Updated: 2026-08-10T16:00:04Z