You need to have CAP_SYS_ADMIN to trigger this overflow but it makes the
static checkers complain so we should fix it. The worry is that
"length" comes from copy_from_user() so we need to check that "length +
offset" can't overflow.
I also changed the min_t() cast to be unsigned instead of signed. Now
that we cap "length" to INT_MAX it doesn't make a difference, but it's a
little easier for reviewers to know that large values aren't cast to
negative.
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>
---
Resending to the linux-n...@lists.infradead.org email address.
diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index 8efdfaa..4376375 100644
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -1206,7 +1206,7 @@ struct nvme_iod *nvme_map_user_pages(struct nvme_dev
*dev, int write,
if (addr & 3)
return ERR_PTR(-EINVAL);
- if (!length)
+ if (!length || length > INT_MAX - PAGE_SIZE)
return ERR_PTR(-EINVAL);
offset = offset_in_page(addr);
@@ -1227,7 +1227,8 @@ struct nvme_iod *nvme_map_user_pages(struct nvme_dev
*dev, int write,
sg_init_table(sg, count);
for (i = 0; i < count; i++) {
sg_set_page(&sg[i], pages[i],
- min_t(int, length, PAGE_SIZE - offset), offset);
+ min_t(unsigned, length, PAGE_SIZE - offset),
+ offset);
length -= (PAGE_SIZE - offset);
offset = 0;
}
--
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