From: Philip Yang <Philip.Yang@xxxxxxx> [ Upstream commit fa582c6f3684ac0098a9d02ddf0ed52a02b37127 ] MMU notifier callback may pass in mm with mm->mm_users==0 when process is exiting, use mmget_no_zero to avoid accessing invalid mm in deferred list work after mm is gone. Signed-off-by: Philip Yang <Philip.Yang@xxxxxxx> Reviewed-by: Felix Kuehling <Felix.Kuehling@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c index 830809b694dd..74e6f613be02 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -2181,6 +2181,8 @@ svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni, if (range->event == MMU_NOTIFY_RELEASE) return true; + if (!mmget_not_zero(mni->mm)) + return true; start = mni->interval_tree.start; last = mni->interval_tree.last; @@ -2207,6 +2209,7 @@ svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni, } svm_range_unlock(prange); + mmput(mni->mm); return true; } -- 2.35.1
