This is a note to let you know that I've just added the patch titled
iommu/amd: Fix BUG when faulting a PROT_NONE VMA
to the 4.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iommu-amd-fix-bug-when-faulting-a-prot_none-vma.patch
and it can be found in the queue-4.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From d14f6fced5f9360edca5a1325ddb7077aab1203b Mon Sep 17 00:00:00 2001
From: Jay Cornwall <jay@xxxxxxxxxxxx>
Date: Wed, 16 Sep 2015 14:10:03 -0500
Subject: iommu/amd: Fix BUG when faulting a PROT_NONE VMA
From: Jay Cornwall <jay@xxxxxxxxxxxx>
commit d14f6fced5f9360edca5a1325ddb7077aab1203b upstream.
handle_mm_fault indirectly triggers a BUG in do_numa_page
when given a VMA without read/write/execute access. Check
this condition in do_fault.
do_fault -> handle_mm_fault -> handle_pte_fault -> do_numa_page
mm/memory.c
3147 static int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
....
3159 /* A PROT_NONE fault should not end up here */
3160 BUG_ON(!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)));
Signed-off-by: Jay Cornwall <jay@xxxxxxxxxxxx>
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/iommu/amd_iommu_v2.c | 7 +++++++
1 file changed, 7 insertions(+)
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -516,6 +516,13 @@ static void do_fault(struct work_struct
goto out;
}
+ if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))) {
+ /* handle_mm_fault would BUG_ON() */
+ up_read(&mm->mmap_sem);
+ handle_fault_error(fault);
+ goto out;
+ }
+
ret = handle_mm_fault(mm, vma, address, write);
if (ret & VM_FAULT_ERROR) {
/* failed to service fault */
Patches currently in stable-queue which might be from jay@xxxxxxxxxxxx are
queue-4.2/iommu-amd-fix-bug-when-faulting-a-prot_none-vma.patch
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