From 21643e69a4c06f7ef155fbc70e3fba13fba4a756 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 4 Nov 2011 21:24:08 +0300 Subject: [PATCH] xen-gntalloc: integer overflow in gntalloc_ioctl_alloc() On 32 bit systems a high value of op.count could lead to an integer overflow in the kzalloc() and gref_ids would be smaller than expected. If the you triggered another integer overflow in "if (gref_size + op.count > limit)" then you'd probably get memory corruption inside add_grefs(). CC: stable@kernel.org Signed-off-by: Dan Carpenter Signed-off-by: Konrad Rzeszutek Wilk --- drivers/xen/gntalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/xen/gntalloc.c b/drivers/xen/gntalloc.c index f6832f46aea4..23c60cf4313e 100644 --- a/drivers/xen/gntalloc.c +++ b/drivers/xen/gntalloc.c @@ -280,7 +280,7 @@ static long gntalloc_ioctl_alloc(struct gntalloc_file_private_data *priv, goto out; } - gref_ids = kzalloc(sizeof(gref_ids[0]) * op.count, GFP_TEMPORARY); + gref_ids = kcalloc(op.count, sizeof(gref_ids[0]), GFP_TEMPORARY); if (!gref_ids) { rc = -ENOMEM; goto out;