iommu/amd: Fix incorrect error handling in amd_iommu_bind_pasid()
In function amd_iommu_bind_pasid(), the control flow jumps
to label out_free when pasid_state->mm and mm is NULL. And
mmput(mm) is called. In function mmput(mm), mm is
referenced without validation. This will result in a NULL
dereference bug. This patch fixes the bug.
Signed-off-by: Pan Bian <bianpan2016@163.com>
Fixes: f0aac63b873b ('iommu/amd: Don't hold a reference to mm_struct')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index 0633439..6629c47 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -696,9 +696,9 @@
out_unregister:
mmu_notifier_unregister(&pasid_state->mn, mm);
+ mmput(mm);
out_free:
- mmput(mm);
free_pasid_state(pasid_state);
out: