iommu/amd: Fix incorrect error handling in amd_iommu_bind_pasid()

commit 73dbd4a4230216b6a5540a362edceae0c9b4876b upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Pan Bian 2017-04-23 18:23:21 +08:00 committed by Greg Kroah-Hartman
parent 48952c6d51
commit aad7041e72

View file

@ -699,9 +699,9 @@ out_clear_state:
out_unregister:
mmu_notifier_unregister(&pasid_state->mn, mm);
mmput(mm);
out_free:
mmput(mm);
free_pasid_state(pasid_state);
out: