{"id":"CVE-2026-64545","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-64545","generatedAt":"2026-10-28T08:10:02.326Z","title":"In the Linux kernel, the following vulnerability has been resolved: net, bpf: check master for NULL in xdp_master_redirect() xdp_master_redirect() dereferences the result of netdev_master_upper_dev_get_rcu() without a NULL check, but that helper returns…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet, bpf: check master for NULL in xdp_master_redirect()\n\nxdp_master_redirect() dereferences the result of\nnetdev_master_upper_dev_get_rcu() without a NULL check, but that helper\nreturns NULL when the receiving device has no upper-master adjacency.\n\nThe reach guard only checks netif_is_bond_slave(). On bond slave release\nbond_upper_dev_unlink() drops the upper-master adjacency before clearing\nIFF_SLAVE, so an XDP_TX reaching xdp_master_redirect() in that window\nstill passes netif_is_bond_slave() while master is already NULL, and\nfaults on master->flags at offset 0xb0:\n\n  BUG: kernel NULL pointer dereference, address: 00000000000000b0\n  RIP: 0010:xdp_master_redirect (net/core/filter.c:4432)\n  Call Trace:\n   xdp_master_redirect (net/core/filter.c:4432)\n   bpf_prog_run_generic_xdp (include/net/xdp.h:700)\n   do_xdp_generic (net/core/dev.c:5608)\n   __netif_receive_skb_one_core (net/core/dev.c:6204)\n   process_backlog (net/core/dev.c:6319)\n   __napi_poll (net/core/dev.c:7729)\n   net_rx_action (net/core/dev.c:7792)\n   handle_softirqs (kernel/softirq.c:622)\n   __dev_queue_xmit (include/linux/bottom_half.h:33)\n   packet_sendmsg (net/packet/af_packet.c:3082)\n   __sys_sendto (net/socket.c:2252)\n  Kernel panic - not syncing: Fatal exception in interrupt\n\nThe missing check dates back to the original code; commit 1921f91298d1\n(\"net, bpf: fix null-ptr-deref in xdp_master_redirect() for down master\")\nlater added the master->flags read where the fault now lands but kept the\nunconditional deref. Check master for NULL before use; a NULL master is\ntreated the same as one that is not up.","published":"2026-07-27T21:17:07.000Z","lastModified":"2026-10-19T21:17:44.000Z","status":"Received","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-476"],"affected":[],"epss":{"score":0.00578,"percentile":0.47417,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.58%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/03b743586a2469744e96e9c1015096d07240935d","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3876318ea54e83eb70982b8280a3c5e4e32269bf","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4edbcacca09f92b85d3951b6add11894b20a84bc","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/89c103d702b25ceb2d097faf854deb47b53b17ff","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c99ca049e910d61ddbd28cc2c47242f2bfbb4970","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e2a56441233131fe18a76001de347ecda217e40c","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e82d8cc4321c373dc46e741cd2dfdaa7921fddb7","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","source":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-457936.html","source":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64545","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}