From: Pan Bian <bianpan2...@163.com> 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 <bianpan2...@163.com> --- drivers/iommu/amd_iommu_v2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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 @@ int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid, out_unregister: mmu_notifier_unregister(&pasid_state->mn, mm); + mmput(mm); out_free: - mmput(mm); free_pasid_state(pasid_state); out: -- 1.9.1