CVE-2026-64577

/// Technical description

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

gtp: check skb_pull_data() return in gtp1u_send_echo_resp()

gtp1u_send_echo_resp() ignores skb_pull_data()'s return value. Its

caller gtp1u_udp_encap_recv() only guarantees 16 bytes (udphdr +

gtp1_header), but the pull requests 20 (gtp1_header_long + udphdr). For

a 16-19 byte echo request the pull fails and returns NULL without

advancing skb->data; execution continues, and the following skb_push()

plus the IP header pushed by iptunnel_xmit() move skb->data below

skb->head, tripping skb_under_panic().

Fix it by dropping the packet when skb_pull_data() fails.

skbuff: skb_under_panic: ...

kernel BUG at net/core/skbuff.c:214!

Call Trace:

skb_push (net/core/skbuff.c:2648)

iptunnel_xmit (net/ipv4/ip_tunnel_core.c:82)

gtp_encap_recv (drivers/net/gtp.c:701 drivers/net/gtp.c:808 drivers/net/gtp.c:920)

udp_queue_rcv_one_skb (net/ipv4/udp.c:2388)

...

Kernel panic - not syncing: Fatal exception in interr

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References