#VU92769 Operation on a resource after expiration or release in Linux kernel - CVE-2019-15794

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Main Vulnerability Database Vulnerabilities #VU92769

#VU92769 Operation on a resource after expiration or release in Linux kernel - CVE-2019-15794

Published: April 24, 2020 / Updated: June 20, 2024


Vulnerability identifier: #VU92769
Vulnerability risk: Low
CVSSv4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear
CVE-ID: CVE-2019-15794
CWE-ID: CWE-672
Exploitation vector: Local access
Exploit availability: Public exploit is available
Vulnerable software:
Linux kernel
Software vendor:
Linux Foundation

Description

The vulnerability allows a local privileged user to execute arbitrary code.

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.


Remediation

Install update from vendor's repository.

External links