This is a note to let you know that I've just added the patch titled
genwqe: Prevent an integer overflow in the ioctl
to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 110080cea0d0e4dfdb0b536e7f8a5633ead6a781 Mon Sep 17 00:00:00 2001
From: Dan Carpenter dan.carpenter@oracle.com Date: Tue, 7 May 2019 11:36:34 +0300 Subject: genwqe: Prevent an integer overflow in the ioctl
There are a couple potential integer overflows here.
round_up(m->size + (m->addr & ~PAGE_MASK), PAGE_SIZE);
The first thing is that the "m->size + (...)" addition could overflow, and the second is that round_up() overflows to zero if the result is within PAGE_SIZE of the type max.
In this code, the "m->size" variable is an u64 but we're saving the result in "map_size" which is an unsigned long and genwqe_user_vmap() takes an unsigned long as well. So I have used ULONG_MAX as the upper bound. From a practical perspective unsigned long is fine/better than trying to change all the types to u64.
Fixes: eaf4722d4645 ("GenWQE Character device and DDCB queue") Signed-off-by: Dan Carpenter dan.carpenter@oracle.com Cc: stable stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/misc/genwqe/card_dev.c | 2 ++ drivers/misc/genwqe/card_utils.c | 4 ++++ 2 files changed, 6 insertions(+)
diff --git a/drivers/misc/genwqe/card_dev.c b/drivers/misc/genwqe/card_dev.c index 8c1b63a4337b..d2098b4d2945 100644 --- a/drivers/misc/genwqe/card_dev.c +++ b/drivers/misc/genwqe/card_dev.c @@ -780,6 +780,8 @@ static int genwqe_pin_mem(struct genwqe_file *cfile, struct genwqe_mem *m)
if ((m->addr == 0x0) || (m->size == 0)) return -EINVAL; + if (m->size > ULONG_MAX - PAGE_SIZE - (m->addr & ~PAGE_MASK)) + return -EINVAL;
map_addr = (m->addr & PAGE_MASK); map_size = round_up(m->size + (m->addr & ~PAGE_MASK), PAGE_SIZE); diff --git a/drivers/misc/genwqe/card_utils.c b/drivers/misc/genwqe/card_utils.c index 89cff9d1012b..7571700abc6e 100644 --- a/drivers/misc/genwqe/card_utils.c +++ b/drivers/misc/genwqe/card_utils.c @@ -586,6 +586,10 @@ int genwqe_user_vmap(struct genwqe_dev *cd, struct dma_mapping *m, void *uaddr, /* determine space needed for page_list. */ data = (unsigned long)uaddr; offs = offset_in_page(data); + if (size > ULONG_MAX - PAGE_SIZE - offs) { + m->size = 0; /* mark unused and not added */ + return -EINVAL; + } m->nr_pages = DIV_ROUND_UP(offs + size, PAGE_SIZE);
m->page_list = kcalloc(m->nr_pages,