Description
Overlayfs in the Linux kernel and shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, both replace vma->vm_file in their mmap handlers. On error the original value is not restored, and the reference is put for the file to which vm_file points. On upstream kernels this is not an issue, as no callers dereference vm_file following after call_mmap() returns an error. However, the aufs patchs change mmap_region() to replace the fput() using a local variable with vma_fput(), which will fput() vm_file, leading to a refcount underflow.
Published: 2020-04-23
Score: 7.1 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
EUVD EUVD EUVD-2019-6717 Overlayfs in the Linux kernel and shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, both replace vma->vm_file in their mmap handlers. On error the original value is not restored, and the reference is put for the file to which vm_file points. On upstream kernels this is not an issue, as no callers dereference vm_file following after call_mmap() returns an error. However, the aufs patchs change mmap_region() to replace the fput() using a local variable with vma_fput(), which will fput() vm_file, leading to a refcount underflow.
Ubuntu USN Ubuntu USN USN-4208-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-4209-1 Linux kernel vulnerabilities
History

Thu, 20 Mar 2025 05:45:00 +0000

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/o:redhat:enterprise_linux:8
Vendors & Products Redhat
Redhat enterprise Linux

Subscriptions

Canonical Ubuntu Linux
Linux Linux Kernel
Redhat Enterprise Linux
cve-icon MITRE

Status: PUBLISHED

Assigner: canonical

Published:

Updated: 2024-09-16T19:52:18.313Z

Reserved: 2019-08-29T00:00:00.000Z

Link: CVE-2019-15794

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2020-04-24T00:15:11.933

Modified: 2024-11-21T04:29:28.880

Link: CVE-2019-15794

cve-icon Redhat

Severity : Moderate

Publid Date: 2019-11-12T00:00:00Z

Links: CVE-2019-15794 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses