From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-68226][LOW] media: cx23885: add ioremap return check and cleanup Date: Mon, 10 Aug 2026 13:16:18 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-68226 X-AL-KERNEL-Priority: LOW X-AL-KERNEL-Severity: LOW X-AL-KERNEL-Base-Severity: LOW X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 1 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: 8fbdca4c99f68734e9b6c030973fb61a11bede15 List-Id: CVE: CVE-2026-68226 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: media: cx23885: add ioremap return check and cleanup Commit: 8fbdca4c99f68734e9b6c030973fb61a11bede15 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8fbdca4c99f68734e9b6c030973fb61a11bede15 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68226 Analysis date: Mon, 10 Aug 2026 13:16:18 -0400 ActionableScore: 1 ActionableScore lower bound: unknown Actionable bucket: Ordinary Moderate / Low-like, auto-close candidate Manual review required: NO Summary: The cx23885 driver failed to check BAR0 MMIO mapping during PCIe device setup, which could lead to a local probe-time NULL pointer dereference and kernel crash, but triggering normally requires privileged device-management control and affected hardware. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-68226 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68226 The original announcement does not normally provide a security severity estimate, CVSS assessment, or enough information to determine whether the reported kernel bug represents a practically relevant security issue. This report was generated by AL-KERNEL, an AI-assisted Linux kernel vulnerability analysis system developed by Alexander Larkin. It combines an autonomous classifier with LLM-assisted technical analysis and a separate ActionableScore mechanism. The purpose of this report is to prioritize Linux kernel CVEs before manual review, identify cases that require prompt investigation, and support automatic closure of issues that are unlikely to have meaningful security impact. Published priority for this report: LOW Manual review required: NO A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-68226 LOW CHECK WITH IMPACT FROM ORIG NN LOW Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';CWE-252;**CWE-476;CWE-703;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '4.7';DESCR 'The cx23885 PCIe media driver could dereference a NULL MMIO mapping during device setup because the return value from pci_ioremap_bar for BAR0 was not checked before dev lmmio and dev bmmio were used. If BAR0 mapping fails, later register access during probe can hit a NULL pointer and cause a kernel oops or crash. For the CVSS the PR:L is used in the paranoid score because a local process may indirectly increase resource pressure or operate in an environment with delegated device control, but reliable triggering normally requires driver probe or device bind control. The issue is not network reachable and requires the affected PCIe hardware or a comparable device setup path. Impact is denial of service only.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like, auto-close candidate (with actual score 1) YES NULLPTR SIMPLEFIX ERRORPATH HARDWARE LINUS NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=1 ## 1. ActionableScore * Conservative score: 1 * Paranoid score: 1 * Final recommended bucket: **Ordinary Moderate / Low-like, auto-close candidate** ## 2. Signal breakdown * Reliable kernel crash / strong DoS: +1 The unchecked `pci_ioremap_bar()` failure can leave `dev->lmmio` NULL and later MMIO register access may cause a NULL pointer dereference during device setup. * Requires admin/root/CAP_* in typical deployments: -2 Reliable triggering normally requires driver probe, module loading, device bind or PCI device management, which is typically administrator-controlled. * Physical-only or rare hardware-only condition: -2 The affected path requires a CX23885/CX23887 PCIe media device or similar test setup, and the failure condition is BAR0 MMIO mapping failure. * Hard or unreliable condition: -1 The vulnerable state depends on `ioremap` failure during probe, which is not a normal attacker-controlled fast path. * Floor applied: score is not allowed to go below 0. A minimal practical DoS concern remains, so the final triage score is 1. ## 3. Reachability analysis The bug is local and probe-time only. It is not network reachable and is not triggered by media packet parsing or ordinary remote input. A normal unprivileged user usually cannot force this path reliably because device probing, driver binding and PCI resource management are privileged operations. Namespaces or containers do not materially lower the privilege requirement unless a container is unusually delegated direct device or driver-management control. The path is only relevant on systems with the affected PCIe hardware or a comparable virtualized PCI setup, and exploitation depends on forcing or naturally hitting BAR0 mapping failure. ## 4. Severity interpretation This behaves like a Low-like or ordinary Moderate kernel robustness issue, not an Important-class vulnerability. The concrete primitive is a NULL pointer dereference on an initialization error path, with no evidence of UAF, OOB write, arbitrary write, object reuse, refcount abuse, information disclosure, or privilege escalation. Theoretical impact is kernel crash only, and realistic attacker control is weak because the failure occurs in a privileged hardware setup path. ## 5. One-sentence report phrase The cx23885 driver failed to check BAR0 MMIO mapping during PCIe device setup, which could lead to a local probe-time NULL pointer dereference and kernel crash, but triggering normally requires privileged device-management control and affected hardware. ## 6. Manual review recommendation NO MANUAL CHECK NEEDED This can be handled as an auto-close candidate for security triage because it is a privileged, hardware-dependent, probe-time NULL dereference with no supported memory corruption or privilege-escalation primitive. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: media: cx23885: add ioremap return check and cleanup Commit: 8fbdca4c99f68734e9b6c030973fb61a11bede15 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8fbdca4c99f68734e9b6c030973fb61a11bede15 Commit description: Add a check for the return value of pci_ioremap_bar() in cx23885_dev_setup(). If ioremap for BAR0 fails, release the already allocated PCI memory region, decrement the device count, and return -ENODEV. This prevents a potential null pointer dereference and ensures proper cleanup on memory mapping failure. Fixes: d19770e ("V4L/DVB (6150): Add CX23885/CX23887 PCIe bridge driver") Cc: stable@vger.kernel.org Signed-off-by: Wang Jun <1742789905@qq.com> Signed-off-by: Hans Verkuil Signed-off-by: Greg Kroah-Hartman Changed files: drivers/media/pci/cx23885/cx23885-core.c Diff excerpt: Not included in this email. See the upstream URL for the full patch. Full patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8fbdca4c99f68734e9b6c030973fb61a11bede15 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-68226 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68226 The original CVE announcement normally does not include a security-level estimate. In particular, it may not contain a CVSS assessment, an impact level, or enough information to determine whether the reported bug is a practically relevant security issue. One purpose of this parallel CVE list is to provide that missing technical and prioritization information. The original goal of the AL-KERNEL project was to prioritize Linux kernel CVE analysis automatically before manual review. The system can also help identify non-security issues that may be suitable for automatic closure. This report was generated by AL-KERNEL, an AI-assisted Linux kernel vulnerability analysis system developed by Alexander Larkin. The first analysis stage combines an autonomous classifier with additional LLM-based analysis. The autonomous classifier runs locally on a CPU and is based on a backpropagation neural network. Together, these mechanisms produce a technical vulnerability description, identify likely weakness types, estimate CVSS severity, and provide input for ActionableScore. Two CVSS estimates are retained because incomplete kernel vulnerability information often permits more than one defensible interpretation: Conservative CVSS vector: AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS score: 4.7 The conservative vector represents a lower-impact interpretation. The Best/paranoid vector intentionally represents a plausible upper-bound interpretation and should not automatically be treated as demonstrated real-world impact. CVSS may also need to be adjusted for a particular Linux deployment, because actual reachability, privileges, enabled kernel configuration, hardware, namespaces, exposed device nodes, and other environmental conditions can differ significantly between systems. A separate ActionableScore mechanism evaluates practical remediation urgency. Its analysis may include reachability, attack prerequisites, subsystem exposure, memory-corruption characteristics, denial-of-service reliability, and possible confidentiality, integrity, or privilege-escalation impact. Conservative ActionableScore: unknown Paranoid ActionableScore: 1 The final base severity is taken directly from the second tab-separated field of the AL-KERNEL classification result. ActionableScore does not replace or independently override that final AL-KERNEL decision, and if ActionableScore adjusted impact level of ALKERNEL, then you would see self-readable flags above like INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7. For an AL-KERNEL result of MODERATE, this report uses the following additional presentation split: ActionableScore below 5 -> MODERATE REGULAR ActionableScore 5 or more -> MODERATE 7.0 The distinction between MODERATE REGULAR and MODERATE 7.0 makes it possible to identify Moderate issues that should receive manual analysis and fixes before lower-priority MODERATE REGULAR issues. In many cases, MODERATE REGULAR fixes may wait for a later rebase or routine update. There is one override in which MODERATE REGULAR becomes MODERATE 7.0 even when the ActionableScore is below 5. When the AL-KERNEL result contains the KPANIC flag, a MODERATE result is always presented as MODERATE 7.0. The KPANIC flag selected with few regexps without usage of AI at all, so it helps to detect cases when Kernel Crash happens and similar (to filter False-Negative results from the LLM usage). KPANIC indicates that a reliable kernel crash, kernel panic, or similarly serious kernel availability impact was identified by the classification workflow. AL-KERNEL base severity for this report: LOW KPANIC detected for this report: NO Published priority for this report (same as in Subject): LOW These results are intended to support engineering triage. They are machine-generated estimates, and cases marked for manual review should be validated by a human security engineer before final disposition. For more info read docs linked from here: https://kernelcve.org/ (and you can submit you own patch there to generate such a report for non-existant CVE-id yet). Note that in many cases this AI tool selects higher severity, than real is (means you can expect Importants instead of Moderate 7.0 or Moderates 7.0 instead of regular Moderates). If you see such cases, please use reply email interface to add additional manual analyses info to this particular CVE. And please, please, let me know when you see Lows instead of Importants or Important instead of Low (because particular for such cases I need to tune this AI tool to make it better for this one and next similar). My contact email for such notifications is alexanjelausa@gmail.com (and both send reply to CVE record itself too and see "reply" button below for howto reply).