{"cve":"CVE-2021-47309","nvd":{"published":"2024-05-21T15:15:18.453","modified":"2026-08-04T10:16:57.623","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: validate lwtstate->data before returning from skb_tunnel_info()\n\nskb_tunnel_info() returns pointer of lwtstate->data as ip_tunnel_info\ntype without validation. lwtstate->data can have various types such as\nmpls_iptunnel_encap, etc and these are not compatible.\nSo skb_tunnel_info() should validate before returning that pointer.\n\nSplat looks like:\nBUG: KASAN: slab-out-of-bounds in vxlan_get_route+0x418/0x4b0 [vxlan]\nRead of size 2 at addr ffff888106ec2698 by task ping/811\n\nCPU: 1 PID: 811 Comm: ping Not tainted 5.13.0+ #1195\nCall Trace:\n dump_stack_lvl+0x56/0x7b\n print_address_description.constprop.8.cold.13+0x13/0x2ee\n ? vxlan_get_route+0x418/0x4b0 [vxlan]\n ? vxlan_get_route+0x418/0x4b0 [vxlan]\n kasan_report.cold.14+0x83/0xdf\n ? vxlan_get_route+0x418/0x4b0 [vxlan]\n vxlan_get_route+0x418/0x4b0 [vxlan]\n [ ... ]\n vxlan_xmit_one+0x148b/0x32b0 [vxlan]\n [ ... ]\n vxlan_xmit+0x25c5/0x4780 [vxlan]\n [ ... ]\n dev_hard_start_xmit+0x1ae/0x6e0\n __dev_queue_xmit+0x1f39/0x31a0\n [ ... ]\n neigh_xmit+0x2f9/0x940\n mpls_xmit+0x911/0x1600 [mpls_iptunnel]\n lwtunnel_xmit+0x18f/0x450\n ip_finish_output2+0x867/0x2040\n [ ... ]","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","score":7.1},"cwes":["CWE-125"],"references":["https://git.kernel.org/stable/c/2179d96ec702cc33ead02a9ce40ece599b8538c5","https://git.kernel.org/stable/c/67a9c94317402b826fc3db32afc8f39336803d97","https://git.kernel.org/stable/c/83bdcfbd968bcc91a0632b7b625e4a9b0cba5e0d","https://git.kernel.org/stable/c/8aa13a86964cdec4fd969ef677c6614ff068641a","https://git.kernel.org/stable/c/8bb1589c89e61e3b182dd546f1021928ebb5c2a6"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2021-47309","score":0.0025,"percentile":0.16405,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}