48da0f67c5
In vma destruction, the following race may occur: Thread 1: Thread 2: i915_vma_destroy(); ... list_del_init(vma->vm_link); ... mutex_unlock(vma->vm->mutex); __i915_vm_release(); release_references(); And in release_reference() we dereference vma->vm to get to the vm gt pointer, leading to a use-after free. However, __i915_vm_release() grabs the vm->mutex so the vm won't be destroyed before vma->vm->mutex is released, so extract the gt pointer under the vm->mutex to avoid the vma->vm dereference in release_references(). v2: Fix a typo in the commit message (Andi Shyti) Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5944 Fixes: e1a7ab4fca0c ("drm/i915: Remove the vm open count") Cc: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com> Cc: Matthew Auld <matthew.auld@intel.com> Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Acked-by: Nirmoy Das <nirmoy.das@intel.con> Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com> Reviewed-by: Matthew Auld <matthew.auld@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220620123659.381772-1-thomas.hellstrom@linux.intel.com (cherry picked from commit 1926a6b75954fc1a8b44d10bd0c67db957b78cf7) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.