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.

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.

kernel: Intel graphics card information leak. kernel: Overlayfs in the Linux kernel and shiftfs not restoring original value on error leading to a refcount underflow kernel: out-of-bounds reads in pinctrl subsystem. kernel: Improper input validation in some Intel(R) Ethernet E810 Adapter drivers kernel: Insufficient access control in some Intel(R) Ethernet E810 Adapter drivers kernel: Uncontrolled resource consumption in some Intel(R) Ethernet E810 Adapter drivers kernel: Fragmentation cache not cleared on reconnection kernel: Reassembling fragments encrypted under different keys kernel: wifi frame payload being parsed incorrectly as an L2 frame kernel: Forwarding EAPOL from unauthenticated wifi client kernel: accepting plaintext data frames in protected networks kernel: not verifying TKIP MIC of fragmented frames kernel: accepting fragmented plaintext frames in protected networks kernel: accepting unencrypted A-MSDU frames that start with RFC1042 header kernel: accepting plaintext broadcast fragments as full frames kernel: reassembling encrypted fragments with non-consecutive packet numbers kernel: reassembling mixed encrypted/plaintext fragments kernel: powerpc: RTAS calls can be used to compromise kernel integrity kernel: the copy-on-write implementation can grant unintended write access because of a race condition in a THP mapcount check kernel: locking inconsistency in drivers/tty/tty_io.c and drivers/tty/tty_jobctrl.c can lead to a read-after-free kernel: buffer overf…

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-5.0, Ubuntu:18.04:LTS: linux-hwe, Ubuntu:18.04:LTS: linux-oem-osp1, Ubuntu:18.04:LTS: linux-oracle-5.0 and 147 more

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.