Linux vulnerability

What happened

In the Linux kernel, the following vulnerability has been resolved: vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu() skb_tunnel_check_pmtu() can change skb->head. Reusing old_iph afer skb_tunnel_check_pmtu() can cause an UAF. Use instead ip_hdr(skb) as done in drivers/net/bareudp.c and drivers/net/geneve.c. Found by Sashiko.

Affected versions

Linux: 4cb47a8644cc9eb8ec81190a50e79e6530d0297f through before 6b8bfce9d2f774d2c2243e0248e03efb99bba6c0 (git); 4cb47a8644cc9eb8ec81190a50e79e6530d0297f through before 9257f56ac47ef1976bcd056cf986a9988eeec67a (git); 4cb47a8644cc9eb8ec81190a50e79e6530d0297f through before 8d435d68d71fb875876b722f4136caf74f2f48bd (git); 4cb47a8644cc9eb8ec81190a50e79e6530d0297f through before dc3bfa050f873371e745bdf478b1f5b738e5733d (git); 4cb47a8644cc9eb8ec81190a50e79e6530d0297f through before 609e63312c29aad18026a1d3222e123d4b6b0feb (git); 4cb47a8644cc9eb8ec81190a50e79e6530d0297f through before 5303925e360527243b46a440a04667826bbc72b7 (git); 4cb47a8644cc9eb8ec81190a50e79e6530d0297f through before a493efd4336cf19122ae0e4cbb3d31b32d70deea (git); 4cb47a8644cc9eb8ec81190a50e79e6530d0297f through before 7d9ef0cb271555d8cf39fefe6c981e1493b25ecf (git); 5.9 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.