[PATCH] iommu/amd: Fix double free of mem-region in error-path

From: Joerg Roedel
Date: Fri Mar 09 2012 - 07:42:08 EST


When ioremap_nocache fails in iommu initialization the code
calls release_mem_region immediatly. But the function is
called again when the propagates into the upper init
functions leading to a double-free. Fix that.

Reported-by: Don Dutile <ddutile@xxxxxxxxxx>
Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
drivers/iommu/amd_iommu_init.c | 10 +---------
1 files changed, 1 insertions(+), 9 deletions(-)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 75653da..526652a 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -358,8 +358,6 @@ static void iommu_disable(struct amd_iommu *iommu)
*/
static u8 * __init iommu_map_mmio_space(u64 address)
{
- u8 *ret;
-
if (!request_mem_region(address, MMIO_REGION_LENGTH, "amd_iommu")) {
pr_err("AMD-Vi: Can not reserve memory region %llx for mmio\n",
address);
@@ -367,13 +365,7 @@ static u8 * __init iommu_map_mmio_space(u64 address)
return NULL;
}

- ret = ioremap_nocache(address, MMIO_REGION_LENGTH);
- if (ret != NULL)
- return ret;
-
- release_mem_region(address, MMIO_REGION_LENGTH);
-
- return NULL;
+ return ioremap_nocache(address, MMIO_REGION_LENGTH);
}

static void __init iommu_unmap_mmio_space(struct amd_iommu *iommu)
--
1.7.5.4


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