From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-45997][LOW] scsi: sd: fix missing put_disk() when device_add(&disk_dev) fails Date: Wed, 27 May 2026 12:03:44 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-45997 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: 0 X-AL-KERNEL-Commit: 262152ec37101f9dc524743ccdbd6c7641d14573 List-Id: CVE: CVE-2026-45997 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: scsi: sd: fix missing put_disk() when device_add(&disk_dev) fails Commit: 262152ec37101f9dc524743ccdbd6c7641d14573 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=262152ec37101f9dc524743ccdbd6c7641d14573 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45997 Analysis date: Wed, 27 May 2026 12:03:44 -0400 ActionableScore: 1 ActionableScore lower bound: 0 Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: A missing `put_disk()` in the SCSI sd probe error path can leak a `gendisk` reference after `device_add()` failure, causing privileged or delegated local resource retention only. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-45997 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45997 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-2026-45997 LOW CHECK 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-772;CWE-404;*CWE-401;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.7';DESCR 'A resource leak can occur in the SCSI sd probe error path when device_add() for the disk device fails. put_device() releases the scsi_disk object, but the gendisk reference was not dropped, leaving the disk object referenced after a failed probe. For the CVSS the PR:L is used only in the paranoid score where a reduced privilege service, delegated container, or local management role can repeatedly trigger SCSI reprobe or hotplug failure paths. The typical case is closer to PR:H because SCSI device probing and failure injection normally require administrative or physical device management. The issue is not network reachable and does not involve UAF, out of bounds access, arbitrary write, information disclosure, or privilege escalation. Impact is denial of service only through resource retention after repeated probe failures.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1) YES SIMPLEFIX ERRORPATH HARDWARE NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=1 ActionableScoreLower=0 ## 1. ActionableScore * Conservative score: 0 * Paranoid score: 1 * Final recommended bucket: **Ordinary Moderate / Low-like**:: ## 2. Signal breakdown Conservative signals: * Availability impact weakly plausible: +1 Repeated failed probe attempts can retain `gendisk` references and cause resource retention. * Requires admin or physical device-management control: -2 SCSI device probing, hotplug, reprobe, or induced `device_add()` failure is normally privileged or physical-device controlled. * Error-path dependent: -1 Triggering requires `device_add(&sdkp->disk_dev)` failure in `sd_probe()`. Paranoid signal: * Delegated device-management concern: +1 Some environments may delegate SCSI hotplug, reprobe, or device management to a service account or container. No signals apply for remote reachability, memory corruption, UAF, OOB access, arbitrary write, information disclosure, privilege escalation, or security-boundary bypass. ## 3. Reachability analysis The bug is local and occurs only during SCSI disk probing when `device_add()` fails. In normal deployments, untrusted users cannot directly trigger SCSI reprobe or fault injection. Namespaces and containers matter only if device-management privileges are delegated. The path is not network reachable and not exposed through normal file IO to a SCSI disk. ## 4. Severity interpretation This behaves like a Low-like cleanup/resource leak. The patch fixes a missing `put_disk()` reference release in an error path. Theoretical impact is resource retention after repeated probe failures. Realistic evidence does not support memory corruption, data corruption, information disclosure, or privilege escalation. ## 5. One-sentence report phrase A missing `put_disk()` in the SCSI sd probe error path can leak a `gendisk` reference after `device_add()` failure, causing privileged or delegated local resource retention only. ## 6. Manual review recommendation NO MANUAL CHECK NEEDED This is an error-path resource leak requiring SCSI device-management control, with no supported memory corruption or privilege-escalation primitive. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: scsi: sd: fix missing put_disk() when device_add(&disk_dev) fails Commit: 262152ec37101f9dc524743ccdbd6c7641d14573 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=262152ec37101f9dc524743ccdbd6c7641d14573 Commit description: If device_add(&sdkp->disk_dev) fails, put_device() runs scsi_disk_release(), which frees the scsi_disk but leaves the gendisk referenced. The device_add_disk() error path in sd_probe() calls put_disk(gd); call put_disk(gd) here to mirror that cleanup. Fixes: 265dfe8 ("scsi: sd: Free scsi_disk device via put_device()") Cc: stable@vger.kernel.org Reviewed-by: John Garry Signed-off-by: Yang Xiuwei Link: https://patch.msgid.link/20260330014952.152776-1-yangxiuwei@kylinos.cn Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman Changed files: drivers/scsi/sd.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=262152ec37101f9dc524743ccdbd6c7641d14573 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-45997 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45997 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:L 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: 0 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).