{"id":"CVE-2026-64545","title":"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 t…","summary":"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 t…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","vendor":"Linux","product":"Linux","affected":["Linux >= 879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 < c99ca049e910d61ddbd28cc2c47242f2bfbb4970","Linux >= 879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 < e2a56441233131fe18a76001de347ecda217e40c","Linux >= 879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 < 3876318ea54e83eb70982b8280a3c5e4e32269bf","Linux >= 879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 < 4edbcacca09f92b85d3951b6add11894b20a84bc","Linux >= 879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 < 03b743586a2469744e96e9c1015096d07240935d","Linux >= 879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 < 89c103d702b25ceb2d097faf854deb47b53b17ff","Linux >= 879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 < e82d8cc4321c373dc46e741cd2dfdaa7921fddb7","Linux 5.15"],"published":"2026-07-27","updated":"2026-09-08","sourceUpdated":"2026-09-08T09:18:20.010","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-64545","references":[{"url":"https://git.kernel.org/stable/c/03b743586a2469744e96e9c1015096d07240935d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3876318ea54e83eb70982b8280a3c5e4e32269bf","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4edbcacca09f92b85d3951b6add11894b20a84bc","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/89c103d702b25ceb2d097faf854deb47b53b17ff","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c99ca049e910d61ddbd28cc2c47242f2bfbb4970","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e2a56441233131fe18a76001de347ecda217e40c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e82d8cc4321c373dc46e741cd2dfdaa7921fddb7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00501,"epssPercentile":0.41779,"ingestedAt":"2026-09-08T15:33:26.950Z","slug":"CVE-2026-64545","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}