From: Dan Carpenter Date: Mon, 13 May 2013 14:59:50 +0000 (+0300) Subject: NVMe: check for integer overflow in nvme_map_user_pages() X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=5460fc03105fbed01fe27aa572d9f65bb410a61d;p=linux-beck.git 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 Signed-off-by: Matthew Wilcox --- diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c index 8efdfaa44a59..437637551d1e 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; }