{"id":"CVE-2026-53051","title":"PCI: tegra194: Fix CBB timeout caused by DBI access before core power-on","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nPCI: tegra194: Fix CBB timeout caused by DBI access before core power-on\n\nWhen PERST# is deasserted twice (assert -> deassert -> assert -> deassert),\na CBB (Control Bac…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 72034050ccf4202cd6558b0afd2474f756ea3b9b < 010983063a806720b45778d191335f8ea864fea3","Linux >= 40e2125381dc11379112485e3eefdd25c6df5375 < b059a41bdd5b202b2b9d7708403fb43c69689e53","Linux >= 40e2125381dc11379112485e3eefdd25c6df5375 < ce899f9c019591b73ef84b9afa332ed53beece25","Linux >= 40e2125381dc11379112485e3eefdd25c6df5375 < 34b3eef48d980cd37b876e128bbf314f69fb5d70","Linux 70212c2300971506e986d95000d2745529cac9d7","Linux >= 6.12.2 < 6.12.91","Linux >= 6.11.11 < 6.12","Linux 6.13"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-06T16:17:18.206478Z"},"published":"2026-06-24","updated":"2026-11-06","sourceUpdated":"2026-11-06T16:23:57.088Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-53051","references":[{"url":"https://git.kernel.org/stable/c/010983063a806720b45778d191335f8ea864fea3"},{"url":"https://git.kernel.org/stable/c/b059a41bdd5b202b2b9d7708403fb43c69689e53"},{"url":"https://git.kernel.org/stable/c/ce899f9c019591b73ef84b9afa332ed53beece25"},{"url":"https://git.kernel.org/stable/c/34b3eef48d980cd37b876e128bbf314f69fb5d70"}],"tags":["cve.org"],"epss":0.00162,"epssPercentile":0.05386,"ingestedAt":"2026-11-06T16:57:43.305Z","slug":"CVE-2026-53051","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nPCI: tegra194: Fix CBB timeout caused by DBI access before core power-on\n\nWhen PERST# is deasserted twice (assert -> deassert -> assert -> deassert),\na CBB (Control Backbone) timeout occurs at DBI register offset 0x8bc\n(PCIE_MISC_CONTROL_1_OFF). This happens because pci_epc_deinit_notify()\nand dw_pcie_ep_cleanup() are called before reset_control_deassert() powers\non the controller core.\n\nThe call chain that causes the timeout:\n\n  pex_ep_event_pex_rst_deassert()\n    pci_epc_deinit_notify()\n      pci_epf_test_epc_deinit()\n        pci_epf_test_clear_bar()\n          pci_epc_clear_bar()\n            dw_pcie_ep_clear_bar()\n              __dw_pcie_ep_reset_bar()\n                dw_pcie_dbi_ro_wr_en()      <- Accesses 0x8bc DBI register\n    reset_control_deassert(pcie->core_rst)  <- Core powered on HERE\n\nThe DBI registers, including PCIE_MISC_CONTROL_1_OFF (0x8bc), are only\naccessible after the controller core is powered on via\nreset_control_deassert(pcie->core_rst). Accessing them before this point\nresults in a CBB timeout because the hardware is not yet operational.\n\nFix this by moving pci_epc_deinit_notify() and dw_pcie_ep_cleanup() to\nafter reset_control_deassert(pcie->core_rst), ensuring the controller is\nfully powered on before any DBI register accesses occur.\n\n## Affected\n\n- `Linux >= 72034050ccf4202cd6558b0afd2474f756ea3b9b < 010983063a806720b45778d191335f8ea864fea3`\n- `Linux >= 40e2125381dc11379112485e3eefdd25c6df5375 < b059a41bdd5b202b2b9d7708403fb43c69689e53`\n- `Linux >= 40e2125381dc11379112485e3eefdd25c6df5375 < ce899f9c019591b73ef84b9afa332ed53beece25`\n- `Linux >= 40e2125381dc11379112485e3eefdd25c6df5375 < 34b3eef48d980cd37b876e128bbf314f69fb5d70`\n- `Linux 70212c2300971506e986d95000d2745529cac9d7`\n- `Linux >= 6.12.2 < 6.12.91`\n- `Linux >= 6.11.11 < 6.12`\n- `Linux 6.13`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}