DEBIAN-CVE-2019-15794

Advisory lineage Upstream: 1 Downstream: 0
Upstream
CVE-2019-15794
Published: 24 Apr 2020, 00:15
Last modified:28 Apr 2026, 20:20

Vulnerability Summary

Overall Risk (default)
medium
27/100
CVSS Score
6.7 MEDIUM
3.1 (osv_debian)
EPSS Score
No data
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

24 Apr 2020, 00:15
Published
Vulnerability first disclosed
28 Apr 2026, 20:20
Last Modified
Vulnerability information updated

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.

CVSS Metrics

  • v3.1•MEDIUM•Score: 6.7CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Affected Systems

  • debian•linux

    all | < 5.16.7-1 | < 5.16.7-1 | < 5.16.7-1

References (1)