[PATCH] powerpc/book3s64: Fix error handling in mm_iommu_do_alloc()
Jan Kara
jack at suse.cz
Wed Dec 11 21:42:26 AEDT 2019
The last jump to free_exit in mm_iommu_do_alloc() happens after page
pointers in struct mm_iommu_table_group_mem_t were already converted to
physical addresses. Thus calling put_page() on these physical addresses
will likely crash. Convert physical addresses back to page pointers
during the error cleanup.
Signed-off-by: Jan Kara <jack at suse.cz>
---
arch/powerpc/mm/book3s64/iommu_api.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
Beware, this is completely untested, spotted just by code audit.
diff --git a/arch/powerpc/mm/book3s64/iommu_api.c b/arch/powerpc/mm/book3s64/iommu_api.c
index 56cc84520577..06c403381c9c 100644
--- a/arch/powerpc/mm/book3s64/iommu_api.c
+++ b/arch/powerpc/mm/book3s64/iommu_api.c
@@ -154,7 +154,7 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua,
(mem2->entries << PAGE_SHIFT)))) {
ret = -EINVAL;
mutex_unlock(&mem_list_mutex);
- goto free_exit;
+ goto convert_exit;
}
}
@@ -166,6 +166,9 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua,
return 0;
+convert_exit:
+ for (i = 0; i < pinned; i++)
+ mem->hpages[i] = pfn_to_page(mem->hpas[i] >> PAGE_SHIFT);
free_exit:
/* free the reference taken */
for (i = 0; i < pinned; i++)
--
2.16.4
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