Overview
- 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.
- Source
- security@ubuntu.com
- NVD status
- Analyzed
Risk scores
CVSS 3.1
- Type
- Primary
- Base score
- 6.7
- Impact score
- 5.9
- Exploitability score
- 0.8
- Vector string
- CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- Severity
- MEDIUM
CVSS 2.0
- Type
- Primary
- Base score
- 7.2
- Impact score
- 10
- Exploitability score
- 3.9
- Vector string
- AV:L/AC:L/Au:N/C:C/I:C/A:C
Social media
- Hype score
- Not currently trending
Configurations
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