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.

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

Configuration 1

cpe:2.3:o:linux:linux_kernel:5.0:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.3:*:*:*:*:*:*:* cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*

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Published : 2020-04-24 12:15

Updated : 2020-05-26 03:18

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NVD link : CVE-2019-15794

Mitre link : CVE-2019-15794

No products.

CWE-672