CVE-2019-15794

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 v3.0 6.7 MEDIUM
CVSS v2.0 7.2 HIGH

6.7^/10

CVSS v3.0 : MEDIUM

Vector :

Exploitability : 0.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required HIGH

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

7.2^/10

CVSS v2.0 : HIGH

Vector : AV:L/AC:L/Au:N/C:C/I:C/A:C

Exploitability : 3.9 / Impact : 10.0

Access Vector LOCAL

Access Complexity LOW

Authentication NONE

Confidentiality Impact COMPLETE

Integrity Impact COMPLETE

Availability Impact COMPLETE

References

Link	Resource
https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=270d16ae48a4dbf1c7e25e94cc3e38b4bea37635	Mailing List Patch Third Party Advisory
https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=ef81780548d20a786cc77ed4203fca146fd81ce3	Mailing List Patch Third Party Advisory
https://usn.ubuntu.com/usn/usn-4208-1	Third Party Advisory
https://usn.ubuntu.com/usn/usn-4209-1	Third Party Advisory

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Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:linux:linux_kernel:5.0:::::::*
	cpe:2.3:o:linux:linux_kernel:5.3:::::::*

Configuration 2 (hide)

OR	cpe:2.3:o:canonical:ubuntu_linux:18.04::::lts:::
	cpe:2.3:o:canonical:ubuntu_linux:19.10:::::::*

Information

Published : 2020-04-23 17:15

Updated : 2020-05-26 08:18

NVD link : CVE-2019-15794

Mitre link : CVE-2019-15794

JSON object : View

CWE

CWE-672

Operation on a Resource after Expiration or Release

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Products Affected

canonical

ubuntu_linux

linux

linux_kernel

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