Linux Linux Kernel Vulnerability Rated 7.8 CVSS

Status: UPDATED  |  Advisory ID: CVE-2026-74666

Key Details

Affected Products, Subsystems & Sectors

What to Know

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

packet: synchronize pressure clearing with ring reconfiguration

packet_set_ring() updates the RX ring state under sk_receive_queue.lock,

but used to publish the tpacket receive mode through po->prot_hook.func

after releasing that lock. packet_poll() and packet_recvmsg() can then

run the pressure clearing path after the ring has been cleared while

still seeing tpacket_rcv, causing __packet_rcv_has_room() to dereference

stale or NULL ring storage.

Move the existing receive hook assignment into the same

sk_receive_queue.lock section as the ring state update. Keep the

assignment otherwise unchanged, including on TX ring reconfiguration, to

avoid adding behavior changes that are not required for the fix.

Serialize packet_recvmsg() pressure clearing with the same queue lock

only after PACKET_SOCK_PRESSURE has been observed. If the flag is clear

and the socket has moved away from tpacket_rcv, packet_set_ring() has

already detached the socket and waited for synchronize_net(), so no new

packet input can set the flag again.

packet_poll() already holds sk_receive_queue.lock, so it uses the new

unlocked helper directly. (NVD)

What to Do

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

References