CVE-2020-25221: Operation on a Resource after Expiration or Release

getgatepage in mm/gup.c in the Linux kernel 5.7.x and 5.8.x before 5.8.7 allows privilege escalation because of incorrect reference counting caused by gate page mishandling of the struct page that backs the vsyscall page. The result is a refcount underflow. This can be triggered by any 64-bit...

CVE-2019-15791

In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, shiftfsbtrfsioctlfdreplace installs an fd referencing a file from the lower filesystem without taking an additional reference to that file. After the btrfs ioctl completes this fd is closed, whi...

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-vmfile in their mmap handlers. On error the original value is not restored, and the reference is put for the file to which vmfile points. On...

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-vmfile in their mmap handlers. On error the original value is not restored, and the reference is put for the file to which vmfile points. On...

CVE-2019-15791

In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, shiftfsbtrfsioctlfdreplace installs an fd referencing a file from the lower filesystem without taking an additional reference to that file. After the btrfs ioctl completes this fd is closed, whi...

Design/Logic Flaw

In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, shiftfsbtrfsioctlfdreplace installs an fd referencing a file from the lower filesystem without taking an additional reference to that file. After the btrfs ioctl completes this fd is closed, whi...

Input validation

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-vmfile in their mmap handlers. On error the original value is not restored, and the reference is put for the file to which vmfile points. On...

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-vmfile in their mmap handlers. On error the original value is not restored, and the reference is put for the file to which vmfile points. On...

CVE-2019-15794 Reference counting error in overlayfs/shiftfs error path when used in conjuction with aufs

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-vmfile in their mmap handlers. On error the original value is not restored, and the reference is put for the file to which vmfile points. On...

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-vmfile in their mmap handlers. On error the original value is not restored, and the reference is put for the file to which vmfile points. On...

CVE-2019-15791

In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, shiftfsbtrfsioctlfdreplace installs an fd referencing a file from the lower filesystem without taking an additional reference to that file. After the btrfs ioctl completes this fd is closed, whi...

CVE-2019-15791

In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, shiftfsbtrfsioctlfdreplace installs an fd referencing a file from the lower filesystem without taking an additional reference to that file. After the btrfs ioctl completes this fd is closed, whi...

CVE-2019-15791

CVE-2019-15791 describes a refcount underflow in the Linux kernel shiftfs implementation caused by a non-upstream patch in Ubuntu 5.0/5.3 kernels: shiftfs_btrfs_ioctl_fd_replace() can create a file descriptor to a lower-filesystem file without an extra reference, and closing the FD after the btrf...

CVE-2019-15791 Reference count underflow in shiftfs

In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, shiftfsbtrfsioctlfdreplace installs an fd referencing a file from the lower filesystem without taking an additional reference to that file. After the btrfs ioctl completes this fd is closed, whi...

CVE-2019-15794: Operation on a Resource after Expiration or Release

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-vmfile in their mmap handlers. On error the original value is not restored, and the reference is put for the file to which vmfile points. On...

CVE-2019-15791: Operation on a Resource after Expiration or Release

In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, shiftfsbtrfsioctlfdreplace installs an fd referencing a file from the lower filesystem without taking an additional reference to that file. After the btrfs ioctl completes this fd is closed, whi...

Ubuntu shiftfs refcount Underflow / Type Confusion

Ubuntu: refcount underflow and type confusion in shiftfs Tested on Ubuntu 19.10, kernel "5.3.0-19-generic 20-Ubuntu". Ubuntu ships a filesystem "shiftfs" in fs/shiftfs.c in the kernel tree that doesn't exist upstream. This filesystem can be mounted from user namespaces, meaning that this is...

UBUNTU-CVE-2019-15791

In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, shiftfsbtrfsioctlfdreplace installs an fd referencing a file from the lower filesystem without taking an additional reference to that file. After the btrfs ioctl completes this fd is closed, whi...

CVE-2019-15791

In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, shiftfsbtrfsioctlfdreplace installs an fd referencing a file from the lower filesystem without taking an additional reference to that file. After the btrfs ioctl completes this fd is closed, whi...

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-vmfile in their mmap handlers. On error the original value is not restored, and the reference is put for the file to which vmfile points. On...