CVE-2026-98968
CVE-2026-98968CVE-2026-98968
Description
In the Linux kernel, the following vulnerability has been resolved:
amt: send the relay's General Query directly from the receive path
An skb queued in a qdisc can outlive the tunnel it references
through a raw pointer in skb->cb. For example, with igmp_qrv set
to 1 on the relay a tunnel lives for 135s, so a netem delay of
180s on the amt device outlives it; when the tunnel expires and is
freed, the subsequent dequeue triggers a use-after-free in
amt_dev_xmit().
BUG: KASAN: slab-use-after-free in amt_dev_xmit+0x2763/0x2e20
Call Trace:
amt_dev_xmit+0x2763/0x2e20 [drivers/net/amt.c:1262]
dev_hard_start_xmit+0x22f/0x620
sch_direct_xmit+0x12e/0xac0
netem_dequeue+0x333/0xc50
net_tx_action+0x35c/0xa60
amt_send_igmp_gq() and amt_send_mld_gq() are only called from
amt_request_handler(), inside the rcu_read_lock_bh() section of
amt_rcv(). amt_request_handler() already has the tunnel the query is
for: it found or created it inside that section. Queuing the query with
dev_q
Scoring
| Last modified | 2026-10-23 |