This is a note to let you know that I've just added the patch titled
s390/pci: fix use after free in dma_init
to the 4.4-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:
s390-pci-fix-use-after-free-in-dma_init.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From dba599091c191d209b1499511a524ad9657c0e5a Mon Sep 17 00:00:00 2001
From: Sebastian Ott <sebott@xxxxxxxxxxxxxxxxxx>
Date: Fri, 15 Apr 2016 09:41:35 +0200
Subject: s390/pci: fix use after free in dma_init
From: Sebastian Ott <sebott@xxxxxxxxxxxxxxxxxx>
commit dba599091c191d209b1499511a524ad9657c0e5a upstream.
After a failure during registration of the dma_table (because of the
function being in error state) we free its memory but don't reset the
associated pointer to zero.
When we then receive a notification from firmware (about the function
being in error state) we'll try to walk and free the dma_table again.
Fix this by resetting the dma_table pointer. In addition to that make
sure that we free the iommu_bitmap when appropriate.
Signed-off-by: Sebastian Ott <sebott@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/s390/pci/pci_dma.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
--- a/arch/s390/pci/pci_dma.c
+++ b/arch/s390/pci/pci_dma.c
@@ -455,7 +455,7 @@ int zpci_dma_init_device(struct zpci_dev
zdev->dma_table = dma_alloc_cpu_table();
if (!zdev->dma_table) {
rc = -ENOMEM;
- goto out_clean;
+ goto out;
}
/*
@@ -475,18 +475,22 @@ int zpci_dma_init_device(struct zpci_dev
zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8);
if (!zdev->iommu_bitmap) {
rc = -ENOMEM;
- goto out_reg;
+ goto free_dma_table;
}
rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
(u64) zdev->dma_table);
if (rc)
- goto out_reg;
- return 0;
+ goto free_bitmap;
-out_reg:
+ return 0;
+free_bitmap:
+ vfree(zdev->iommu_bitmap);
+ zdev->iommu_bitmap = NULL;
+free_dma_table:
dma_free_cpu_table(zdev->dma_table);
-out_clean:
+ zdev->dma_table = NULL;
+out:
return rc;
}
Patches currently in stable-queue which might be from sebott@xxxxxxxxxxxxxxxxxx are
queue-4.4/s390-pci-fix-use-after-free-in-dma_init.patch