CVEvulnerability

CVE-2019-15794

6.7 MEDIUM Published 2020-04-24 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2020-04-24
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
7.1 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
CVSS 3.1 ([email protected])
6.7 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0 ([email protected])
7.2 HIGH — AV:L/AC:L/Au:N/C:C/I:C/A:C
Weaknesses
CWE-672

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.

Affected configurations

• linux linux kernel 5.0 • linux linux kernel 5.3 • canonical ubuntu linux 18.04 • canonical ubuntu linux 19.10

Related

Weakness · CWE (1)

  • CWE-672 Operation on a Resource after Expiration or Release weakness

References