From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-97507][MODERATE REGULAR] media: dm1105: fix missing error check for dma_alloc_coherent [ Upstream Date: Thu, 24 Sep 2026 21:27:17 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-97507 X-AL-KERNEL-Priority: MODERATE REGULAR X-AL-KERNEL-Severity: MODERATE REGULAR X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 1 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: 07d6a76a17b550e94ca5cc0060ad6e77952390f2 List-Id: CVE: CVE-2026-97507 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: media: dm1105: fix missing error check for dma_alloc_coherent [ Upstream Commit: 07d6a76a17b550e94ca5cc0060ad6e77952390f2 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=07d6a76a17b550e94ca5cc0060ad6e77952390f2 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97507 Analysis date: Thu, 24 Sep 2026 21:27:17 -0400 ActionableScore: 1 ActionableScore lower bound: unknown Actionable bucket: Ordinary Moderate Manual review required: NO Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-97507 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97507 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: MODERATE REGULAR 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-2026-97507 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-97507 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:L/I:L/A:H';CWE-252;**CWE-476;CWE-703;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.8';DESCR 'An unchecked failure from dm1105_dma_map can leave the DM1105 driver without a valid coherent DMA buffer while initialization continues and enables DMA related hardware state. If dma_alloc_coherent fails, later DMA setup or transfers can use a NULL or invalid DMA mapping and may cause a kernel oops, device failure, or system crash. For the CVSS the PR:L value is used because a local user or process is needed to create the memory pressure or fragmentation required for reliable allocation failure. The issue is not directly network reachable. Impact is at least local denial of service. Invalid DMA after an allocation failure may also create limited confidentiality or integrity risk, but the shown patch does not demonstrate attacker control of the DMA address or a reliable privilege escalation primitive. YES REQUIRES MANUAL CHECK';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 1) YES OOB NOMEMCHK DMAorINTERRUPT HARDWARE LINUS MEMORY DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=1 PrimitiveClass=CLASS_C RealUAF=NO HostAdminRequired=UNKNOWN NamespaceScopedPrivilege=UNKNOWN ImportantCandidate=NO ManualReview=RECOMMENDED AutoDowngradeAllowed=YES 1. ActionableScore * Raw conservative score: 1 * Conservative score: 1 * Raw paranoid score: 1 * Paranoid score: 1 * Final recommended bucket: **Ordinary Moderate**:: The conservative and paranoid scores are identical because the supplied patch establishes an invalid DMA initialization state, but does not establish a controllable DMA target, attacker-controlled DMA payload, kernel memory disclosure, active-object lifetime violation, or post-failure memory corruption primitive. 2. Signal breakdown * +1 Weak or indirect corruption candidate. The unchecked dm1105_dma_map result allows initialization to continue after dma_alloc_coherent failure. The device may subsequently be configured for DMA without a valid coherent buffer, creating an invalid DMA or NULL-related failure path. * +0 Reliable kernel crash or strong host-wide DoS. The commit mentions a kernel oops or invalid hardware access, but does not establish a reliable host-wide panic rather than a driver failure, device failure, or recoverable Oops. * +0 Local unprivileged trigger. A local process may contribute memory pressure or fragmentation, but the supplied evidence does not establish that the same unprivileged actor can reliably cause DM1105 initialization, probe, reload, or reset at the required time. * +0 Remote reachability. No network-reachable path is established. DVB or capture input is mediated by the physical device and does not directly cause dma_alloc_coherent failure. * +0 Constrained overwrite. The patch does not show that the hardware receives an attacker-controlled DMA address or payload, nor that a failed allocation leaves a writable valid target address. * +0 Confidentiality or integrity impact. Invalid DMA is concerning in principle, but the shown code does not establish disclosure, an unauthorized write to protected memory, or a privilege-escalation path. * +0 Strong exploitation leverage. Controlled reclaim, arbitrary write, directed DMA, callback control, refcount manipulation, and object replacement are not demonstrated. * No negative hardware penalty was applied. The vulnerable path requires a DM1105 device, but the supplied evidence does not establish that the hardware is sufficiently rare or that physical attacker access is required. 3. Reachability analysis The vulnerable operation occurs during DM1105 hardware initialization. A complete trigger requires both a DM1105 device using this driver and failure of dma_alloc_coherent during initialization. A local user may be able to create memory pressure in some deployments, but the patch does not establish that an ordinary user can reliably trigger device probe, driver reload, reset, or initialization while controlling allocation conditions. Conversely, host-admin-equivalent privilege is not positively established as a required part of every possible trigger sequence. Therefore, HostAdminRequired is UNKNOWN. No namespace-scoped privilege path is shown. The driver operates on a host PCI device, and ordinary network or user namespaces do not establish control over the complete device initialization and DMA setup sequence. NamespaceScopedPrivilege is UNKNOWN. There is no direct network trigger. External media input may reach the physical capture device, but it does not by itself establish the allocation failure prerequisite or direct attacker control over DMA addressing. 4. Primitive and severity interpretation The established primitive is an unchecked allocation failure followed by continued device initialization. If dm1105_dma_map fails, the driver can proceed to program DMA-related hardware state without a valid coherent DMA allocation. This is not a UAF, stale-object use, double release, refcount mutation, ownership violation, or authorization bypass. The affected state is fixed driver DMA state rather than an active stale structured object subject to attacker-controlled replacement. The demonstrated consequence is a kernel Oops, invalid hardware access, driver failure, or potentially a system availability failure. A stronger consequence such as corruption of arbitrary host memory remains speculative because the supplied patch does not show the failure behavior of dm1105_dma_map, the resulting DMA address value, IOMMU behavior, or attacker control over capture data and DMA destination. PrimitiveClass is CLASS_C because the evidence primarily establishes invalid-state and crash or DoS behavior without an independently useful corruption primitive. ImportantCandidate is NO because meaningful exploitation leverage beyond failure of the driver or kernel is not established. AutoDowngradeAllowed is YES because no concrete UAF, controlled DMA write, repeated lifetime mutation, security-boundary bypass, or active corruption primitive remains unresolved. 5. One-sentence report phrase An unchecked DMA allocation failure in the DM1105 driver can allow initialization to continue with invalid DMA state, causing a kernel Oops or device failure, but the patch does not establish an attacker-controlled memory-corruption or privilege-escalation primitive. 6. Manual review recommendation MANUAL CHECK RECOMMENDED Inspect dm1105_dma_map, dm1105_set_dma_addr, DMA address initialization, and IOMMU behavior to determine whether allocation failure can leave a nonzero, stale, or attacker-influenced DMA address that could permit an actual DMA write beyond the expected invalid-access or crash behavior. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: media: dm1105: fix missing error check for dma_alloc_coherent [ Upstream Commit: 07d6a76a17b550e94ca5cc0060ad6e77952390f2 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=07d6a76a17b550e94ca5cc0060ad6e77952390f2 Changed files: drivers/media/pci/dm1105/dm1105.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=07d6a76a17b550e94ca5cc0060ad6e77952390f2 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-97507 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97507 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:L/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:L/I:L/A:H The Best / paranoid CVSS score: 5.8 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: MODERATE KPANIC detected for this report: NO Published priority for this report (same as in Subject): MODERATE REGULAR 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).