Vulnerability in Linux Kernel
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H.
EPSS exploit prediction
EPSS: 0.012 (66.6th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 67th percentile — 66.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000
Affected products
- Linux Kernel — versions 5.0, 5.3
- Canonical Ubuntu Linux — versions 18.04, 19.10
- Ubuntu Linux Kernel — versions 5.3 kernel, 5.0 kernel
Weakness classification (CWE)
References
- git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/ (Patch, Mailing List, Third Party Advisory)
- git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/ (Patch, Mailing List, Third Party Advisory)
- usn.ubuntu.com/usn/usn-4208-1 (Third Party Advisory)
- usn.ubuntu.com/usn/usn-4209-1 (Third Party Advisory)
Frequently asked questions
- What is CVE-2019-15794?
- CVE-2019-15794 is a high-severity vulnerability in Linux Kernel, classified under Operation on a Resource after Expiration or Release. CVSS score: 7.1/10. Published 2020-04-24.
- How severe is CVE-2019-15794?
- High severity. CVSS v3 base score is 7.1 out of 10.