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authorDan Carpenter <dan.carpenter@oracle.com>2013-05-13 17:59:50 +0300
committerMatthew Wilcox <matthew.r.wilcox@intel.com>2013-05-17 09:11:03 -0400
commit5460fc03105fbed01fe27aa572d9f65bb410a61d (patch)
tree0e4e62a7fe314ceaa89a7966ef7c2d770686d361 /drivers/block
parent5be37bf9c17ffad0590a4044dbb110fe08066923 (diff)
NVMe: check for integer overflow in nvme_map_user_pages()
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.carpenter@oracle.com> Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/nvme-core.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index 8efdfaa44a5..437637551d1 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;
}