Patch-mainline: v6.0-rc4
Git-commit: e9ea0b30ada008f4e65933f449db6894832cb242
References: git-fixes
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Thu, 1 Sep 2022 18:35:20 +0300
Subject: [PATCH] xen/grants: prevent integer overflow in
gnttab_dma_alloc_pages()
The change from kcalloc() to kvmalloc() means that arg->nr_pages
might now be large enough that the "args->nr_pages << PAGE_SHIFT" can
result in an integer overflow.
Fixes: b3f7931f5c61 ("xen/gntdev: switch from kcalloc() to kvcalloc()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/YxDROJqu/RPvR0bi@kili
Signed-off-by: Juergen Gross <jgross@suse.com>
---
drivers/xen/grant-table.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 738029de3c67..e1ec725c2819 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -1047,6 +1047,9 @@ int gnttab_dma_alloc_pages(struct gnttab_dma_alloc_args *args)
size_t size;
int i, ret;
+ if (args->nr_pages < 0 || args->nr_pages > (INT_MAX >> PAGE_SHIFT))
+ return -ENOMEM;
+
size = args->nr_pages << PAGE_SHIFT;
if (args->coherent)
args->vaddr = dma_alloc_coherent(args->dev, size,
--
2.35.3