In the Linux kernel, the following vulnerability has been resolved:

android: binder: stop saving a pointer to the VMA

Do not record a pointer to a VMA outside of the mmap_lock for later use. 
This is unsafe and there are a number of failure paths *after* the
recorded VMA pointer may be freed during setup.  There is no callback to
the driver to clear the saved pointer from generic mm code.  Furthermore,
the VMA pointer may become stale if any number of VMA operations end up
freeing the VMA so saving it was fragile to being with.

Instead, change the binder_alloc struct to record the start address of the
VMA and use vma_lookup() to get the vma when needed.  Add lockdep
mmap_lock checks on updates to the vma pointer to ensure the lock is held
and depend on that lock for synchronization of readers and writers - which
was already the case anyways, so the smp_wmb()/smp_rmb() was not
necessary.

[[email protected]: fix drivers/android/binder_alloc_selftest.c]

Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.

kernel.org: https://git.kernel.org/stable/c/1ec3f76a436d750fd5023caec5da0494fc2870d2

kernel.org: https://git.kernel.org/stable/c/622ef885a89ad04cfb76ee478fb44f051125d1f1

kernel.org: https://git.kernel.org/stable/c/925e6b6f82c9c80ab3c17acbde8d16f349da7d26

kernel.org: https://git.kernel.org/stable/c/a43cfc87caaf46710c8027a8c23b8a55f1078f19

In the Linux kernel, the following vulnerability has been resolved:

android: binder: stop saving a pointer to the VMA

Do not record a pointer to a VMA outside of the mmap_lock for later use. 
This is unsafe and there are a number of failure paths *after* the
recorded VMA pointer may be freed during setup.  There is no callback to
the driver to clear the saved pointer from generic mm code.  Furthermore,
the VMA pointer may become stale if any number of VMA operations end up
freeing the VMA so saving it was fragile to being with.

Instead, change the binder_alloc struct to record the start address of the
VMA and use vma_lookup() to get the vma when needed.  Add lockdep
mmap_lock checks on updates to the vma pointer to ensure the lock is held
and depend on that lock for synchronization of readers and writers - which
was already the case anyways, so the smp_wmb()/smp_rmb() was not
necessary.

[[email protected]: fix drivers/android/binder_alloc_selftest.c]

https://git.kernel.org/stable/c/1ec3f76a436d750fd5023caec5da0494fc2870d2

https://git.kernel.org/stable/c/622ef885a89ad04cfb76ee478fb44f051125d1f1

https://git.kernel.org/stable/c/925e6b6f82c9c80ab3c17acbde8d16f349da7d26

https://git.kernel.org/stable/c/a43cfc87caaf46710c8027a8c23b8a55f1078f19