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authorRob Clark <robdclark@chromium.org>2023-01-27 12:05:31 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-02-15 17:22:20 +0100
commitb591abac78e25269b12e3d7170c99463f8c5cb02 (patch)
tree942ede2f848c428dec4141aed6209a517c22ef0f
parent5c4d4a83bf1a862d80c1efff1c6e3ce33b501e2e (diff)
drm/i915: Fix potential bit_17 double-free
commit 7057a8f126f14f14b040faecfa220fd27c6c2f85 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: 2850748ef876 ("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 10e0cbaaf1104f449d695c80bcacf930dcd3c42e) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/gpu/drm/i915/gem/i915_gem_tiling.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_tiling.c b/drivers/gpu/drm/i915/gem/i915_gem_tiling.c
index ffcaee74a249..545fa703d975 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_tiling.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_tiling.c
@@ -296,10 +296,6 @@ i915_gem_object_set_tiling(struct drm_i915_gem_object *obj,
spin_unlock(&obj->vma.lock);
obj->tiling_and_stride = tiling | stride;
- i915_gem_object_unlock(obj);
-
- /* Force the fence to be reacquired for GTT access */
- i915_gem_object_release_mmap_gtt(obj);
/* Try to preallocate memory required to save swizzling on put-pages */
if (i915_gem_object_needs_bit17_swizzle(obj)) {
@@ -312,6 +308,11 @@ i915_gem_object_set_tiling(struct drm_i915_gem_object *obj,
obj->bit_17 = NULL;
}
+ i915_gem_object_unlock(obj);
+
+ /* Force the fence to be reacquired for GTT access */
+ i915_gem_object_release_mmap_gtt(obj);
+
return 0;
}