{"id":"CVE-2026-64545","state":"PUBLISHED","title":"net, bpf: check master for NULL in xdp_master_redirect()","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.","publishedAt":"2026-07-27T20:10:36.659Z","updatedAt":"2026-10-19T20:48:39.877Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"879af96ffd72706c6e3278ea6b45b0b0e37ec5d7","status":"affected","lessThan":"c99ca049e910d61ddbd28cc2c47242f2bfbb4970","versionType":"git"},{"version":"879af96ffd72706c6e3278ea6b45b0b0e37ec5d7","status":"affected","lessThan":"e2a56441233131fe18a76001de347ecda217e40c","versionType":"git"},{"version":"879af96ffd72706c6e3278ea6b45b0b0e37ec5d7","status":"affected","lessThan":"3876318ea54e83eb70982b8280a3c5e4e32269bf","versionType":"git"},{"version":"879af96ffd72706c6e3278ea6b45b0b0e37ec5d7","status":"affected","lessThan":"4edbcacca09f92b85d3951b6add11894b20a84bc","versionType":"git"},{"version":"879af96ffd72706c6e3278ea6b45b0b0e37ec5d7","status":"affected","lessThan":"03b743586a2469744e96e9c1015096d07240935d","versionType":"git"},{"version":"879af96ffd72706c6e3278ea6b45b0b0e37ec5d7","status":"affected","lessThan":"89c103d702b25ceb2d097faf854deb47b53b17ff","versionType":"git"},{"version":"879af96ffd72706c6e3278ea6b45b0b0e37ec5d7","status":"affected","lessThan":"e82d8cc4321c373dc46e741cd2dfdaa7921fddb7","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/filter.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.15","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/filter.c"]}],"references":["https://git.kernel.org/stable/c/c99ca049e910d61ddbd28cc2c47242f2bfbb4970","https://git.kernel.org/stable/c/e2a56441233131fe18a76001de347ecda217e40c","https://git.kernel.org/stable/c/3876318ea54e83eb70982b8280a3c5e4e32269bf","https://git.kernel.org/stable/c/4edbcacca09f92b85d3951b6add11894b20a84bc","https://git.kernel.org/stable/c/03b743586a2469744e96e9c1015096d07240935d","https://git.kernel.org/stable/c/89c103d702b25ceb2d097faf854deb47b53b17ff","https://git.kernel.org/stable/c/e82d8cc4321c373dc46e741cd2dfdaa7921fddb7","https://cert-portal.siemens.com/productcert/html/ssa-019113.html","https://cert-portal.siemens.com/productcert/html/ssa-457936.html"],"weaknesses":["CWE-476"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64545.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64545","state":"PUBLISHED","datePublished":"2026-07-27T20:10:36.659Z","dateUpdated":"2026-10-19T20:48:39.877Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.795Z"},"containers":{"cna":{"title":"net, bpf: check master for NULL in xdp_master_redirect()","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"879af96ffd72706c6e3278ea6b45b0b0e37ec5d7","status":"affected","lessThan":"c99ca049e910d61ddbd28cc2c47242f2bfbb4970","versionType":"git"},{"version":"879af96ffd72706c6e3278ea6b45b0b0e37ec5d7","status":"affected","lessThan":"e2a56441233131fe18a76001de347ecda217e40c","versionType":"git"},{"version":"879af96ffd72706c6e3278ea6b45b0b0e37ec5d7","status":"affected","lessThan":"3876318ea54e83eb70982b8280a3c5e4e32269bf","versionType":"git"},{"version":"879af96ffd72706c6e3278ea6b45b0b0e37ec5d7","status":"affected","lessThan":"4edbcacca09f92b85d3951b6add11894b20a84bc","versionType":"git"},{"version":"879af96ffd72706c6e3278ea6b45b0b0e37ec5d7","status":"affected","lessThan":"03b743586a2469744e96e9c1015096d07240935d","versionType":"git"},{"version":"879af96ffd72706c6e3278ea6b45b0b0e37ec5d7","status":"affected","lessThan":"89c103d702b25ceb2d097faf854deb47b53b17ff","versionType":"git"},{"version":"879af96ffd72706c6e3278ea6b45b0b0e37ec5d7","status":"affected","lessThan":"e82d8cc4321c373dc46e741cd2dfdaa7921fddb7","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/filter.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.15","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/filter.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/c99ca049e910d61ddbd28cc2c47242f2bfbb4970"},{"url":"https://git.kernel.org/stable/c/e2a56441233131fe18a76001de347ecda217e40c"},{"url":"https://git.kernel.org/stable/c/3876318ea54e83eb70982b8280a3c5e4e32269bf"},{"url":"https://git.kernel.org/stable/c/4edbcacca09f92b85d3951b6add11894b20a84bc"},{"url":"https://git.kernel.org/stable/c/03b743586a2469744e96e9c1015096d07240935d"},{"url":"https://git.kernel.org/stable/c/89c103d702b25ceb2d097faf854deb47b53b17ff"},{"url":"https://git.kernel.org/stable/c/e82d8cc4321c373dc46e741cd2dfdaa7921fddb7"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - The faulting path is the XDP receive hook — packets arriving on a bond slave drive `bpf_prog_run_xdp`/`do_xdp_generic` → `xdp_master_redirect()`, so a remote attacker sending traffic to a bonded interface running an XDP_TX program (XDP load balancers/DDoS scrubbers on bonded uplinks are a mainstream deployment) supplies the triggering packets with no local access.\nAC:L - The attacker controls the packet side of the race and can sustain line-rate traffic so the multi-microsecond window between adjacency teardown and `IFF_SLAVE` clearing is hit essentially deterministically; where the attacker also holds the network configuration side (container/netns with bond and XDP control) both sides of the race are attacker-driven, which the kernel guidance classes as Low.\nPR:N - No credentials or authentication are needed to send frames to a bonded interface, and the fault occurs in softirq during receive processing before any socket, filesystem, or user-level authorization is consulted — matching the PR:N treatment of the sibling fix CVE-2026-53069 in this same function.\nUI:N - No victim action is required; the slave-release window is reached by routine and externally-induced events (bond reconfiguration, `bond_enslave` rollback, NIC hotplug/`NETDEV_UNREGISTER`), and the attacker need only keep traffic flowing.\nS:U - The NULL dereference and its consequences are confined to the kernel's own security authority; no hypervisor, IOMMU, or sandbox boundary is crossed.\nC:N - The bug is a read of `master->flags` at fixed offset 0xb0 from a NULL pointer, which faults immediately; no memory contents are returned to the attacker and no kernel addresses are disclosed.\nI:N - There is no write primitive — the defect is a read-side dereference that faults before `master->netdev_ops->ndo_xdp_get_xmit_slave()` is reached, so no kernel data or control flow is modified.\nA:H - The dereference happens in softirq/interrupt context, producing \"Kernel panic - not syncing: Fatal exception in interrupt\" — a complete system crash rather than a recoverable oops, and it can be re-triggered on every reboot as long as traffic and bond reconfiguration continue."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:57:22.161Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"5.15.212"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"affected":[{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIPLUS S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIPLUS S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]}],"references":[{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-457936.html"}],"providerMetadata":{"shortName":"siemens-SADP","orgId":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","dateUpdated":"2026-10-15T01:23:53.420Z"},"x_adpType":"supplier"},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64545","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:42:14.941919Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-476","lang":"en","type":"CWE","description":"CWE-476 NULL Pointer Dereference"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:48:39.877Z"}}]}}}