The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
Thanks, Sasha
------------------ original commit in Linus's tree ------------------
From db7bbd13f08774cde0332c705f042e327fe21e73 Mon Sep 17 00:00:00 2001 From: Nirmoy Das nirmoy.das@intel.com Date: Mon, 19 Feb 2024 13:50:47 +0100 Subject: [PATCH] drm/i915: Check before removing mm notifier
Error in mmu_interval_notifier_insert() can leave a NULL notifier.mm pointer. Catch that and return early.
Fixes: ed29c2691188 ("drm/i915: Fix userptr so we do not have to worry about obj->mm.lock, v7.") Cc: stable@vger.kernel.org # v5.13+ [tursulin: Added Fixes and cc stable.] Cc: Andi Shyti andi.shyti@linux.intel.com Cc: Shawn Lee shawn.c.lee@intel.com Signed-off-by: Nirmoy Das nirmoy.das@intel.com Reviewed-by: Rodrigo Vivi rodrigo.vivi@intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20240219125047.28906-1-nirmoy.... Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@intel.com --- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c index 0e21ce9d3e5ac..61abfb505766d 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -349,6 +349,9 @@ i915_gem_userptr_release(struct drm_i915_gem_object *obj) { GEM_WARN_ON(obj->userptr.page_ref);
+ if (!obj->userptr.notifier.mm) + return; + mmu_interval_notifier_remove(&obj->userptr.notifier); obj->userptr.notifier.mm = NULL; }