CVE-2026-72126

Status: UPDATED  |  Advisory ID: CVE-2026-72126

Key Details

Affected Products, Subsystems & Sectors

What to Know

In the Linux kernel, the following vulnerability has been resolved:

can: isotp: use unconditional synchronize_rcu() in isotp_release()

isotp_notify() unregisters the (RCU) CAN filters via can_rx_unregister()

and clears so->bound without waiting for a grace period. isotp_release()

uses so->bound to decide whether it needs to call synchronize_rcu()

before cancelling so->rxtimer, so when NETDEV_UNREGISTER runs first it

skips that synchronize_rcu() and can cancel the timer while an

in-flight isotp_rcv() is still executing and about to re-arm it via

isotp_send_fc(), leading to a use-after-free timer callback on the

freed socket.

sakisho-bot remarked a problem with rtnl_lock held in isotp_notify(),

therefore make isotp_release() always call synchronize_rcu() before

cancelling the timers, regardless of so->bound. This still closes the

original race (isotp_notify() clearing so->bound without waiting for

in-flight isotp_rcv() callers before isotp_release() cancels the RX

timer) without adding any RCU wait to the netdevice notifier path. (NVD)

What to Do

Monitor Linux's web page for any future patch releases.

References