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CVE-2019-15794

Reference counting error in overlayfs/shiftfs error path when used in conjuction with aufs PUBLISHED

Description (CNA)

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.

Affected (CNA)

Vendor / productVersions
Ubuntu / Linux kernelaffected 5.3 kernel before 5.3.0-24.26; affected 5.0 kernel before 5.0.0-37.40

CWE

CWE-672

References

ADP enrichment

CVE

No English description supplied.