drm/i915: Fix potential bit_17 double-free

stable inclusion
from stable-v5.10.168
commit b591abac78e25269b12e3d7170c99463f8c5cb02
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7URR4

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b591abac78e25269b12e3d7170c99463f8c5cb02



----------------------------------------------------

commit 7057a8f1 upstream.

A userspace with multiple threads racing I915_GEM_SET_TILING to set the
tiling to I915_TILING_NONE could trigger a double free of the bit_17
bitmask.  (Or conversely leak memory on the transition to tiled.)  Move
allocation/free'ing of the bitmask within the section protected by the
obj lock.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Fixes: 2850748e ("drm/i915: Pull i915_vma_pin under the vm->mutex")
Cc: <stable@vger.kernel.org> # v5.5+
[tursulin: Correct fixes tag and added cc stable.]
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230127200550.3531984-1-robdclark@gmail.com


(cherry picked from commit 10e0cbaa)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: zhaoxiaoqiang11 <zhaoxiaoqiang11@jd.com>