From: Jacob Pan jacob.jun.pan@linux.intel.com
[ Upstream commit 902baf61adf6b187f0a6b789e70d788ea71ff5bc ]
Move canonical address check before mmget_not_zero() to avoid mm reference leak.
Fixes: 9d8c3af31607 ("iommu/vt-d: IOMMU Page Request needs to check if address is canonical.") Signed-off-by: Jacob Pan jacob.jun.pan@linux.intel.com Acked-by: Lu Baolu baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iommu/intel-svm.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c index 5944d3b4dca37..ef3aadec980ee 100644 --- a/drivers/iommu/intel-svm.c +++ b/drivers/iommu/intel-svm.c @@ -620,14 +620,15 @@ static irqreturn_t prq_event_thread(int irq, void *d) * any faults on kernel addresses. */ if (!svm->mm) goto bad_req; - /* If the mm is already defunct, don't handle faults. */ - if (!mmget_not_zero(svm->mm)) - goto bad_req;
/* If address is not canonical, return invalid response */ if (!is_canonical_address(address)) goto bad_req;
+ /* If the mm is already defunct, don't handle faults. */ + if (!mmget_not_zero(svm->mm)) + goto bad_req; + down_read(&svm->mm->mmap_sem); vma = find_extend_vma(svm->mm, address); if (!vma || address < vma->vm_start)