{"id":"CVE-2026-64545","summary":"net, bpf: check master for NULL in xdp_master_redirect()","details":"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-\u003eflags 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-\u003eflags 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.","modified":"2026-08-18T03:31:23.280172188Z","published":"2026-07-27T20:10:36.659Z","related":["openSUSE-SU-2026:11476-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64545.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/03b743586a2469744e96e9c1015096d07240935d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3876318ea54e83eb70982b8280a3c5e4e32269bf"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4edbcacca09f92b85d3951b6add11894b20a84bc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/89c103d702b25ceb2d097faf854deb47b53b17ff"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c99ca049e910d61ddbd28cc2c47242f2bfbb4970"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e2a56441233131fe18a76001de347ecda217e40c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e82d8cc4321c373dc46e741cd2dfdaa7921fddb7"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64545.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64545"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"879af96ffd72706c6e3278ea6b45b0b0e37ec5d7"},{"fixed":"c99ca049e910d61ddbd28cc2c47242f2bfbb4970"},{"fixed":"e2a56441233131fe18a76001de347ecda217e40c"},{"fixed":"3876318ea54e83eb70982b8280a3c5e4e32269bf"},{"fixed":"4edbcacca09f92b85d3951b6add11894b20a84bc"},{"fixed":"03b743586a2469744e96e9c1015096d07240935d"},{"fixed":"89c103d702b25ceb2d097faf854deb47b53b17ff"},{"fixed":"e82d8cc4321c373dc46e741cd2dfdaa7921fddb7"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64545.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.15.0"},{"fixed":"5.15.212"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.178"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.145"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.97"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.40"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64545.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}