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: f0aac63b87 ('iommu/amd: Don't hold a reference to mm_struct')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Pan Bian 2017-04-23 18:23:21 +08:00 committed by Joerg Roedel
parent 5a7ad1146c
commit 73dbd4a423

View File

@ -696,9 +696,9 @@ out_clear_state:
out_unregister:
mmu_notifier_unregister(&pasid_state->mn, mm);
mmput(mm);
out_free:
mmput(mm);
free_pasid_state(pasid_state);
out: