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| author | Dan Carpenter <dan.carpenter@oracle.com> | 2019-05-07 11:36:34 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-24 21:40:10 +0300 |
| commit | 110080cea0d0e4dfdb0b536e7f8a5633ead6a781 (patch) | |
| tree | 175c7135a67aeec7d97deae544bb373b8887ad04 /drivers/misc/genwqe/card_utils.c | |
| parent | 1c7ebeabc9e5ee12e42075a597de40fdb9059530 (diff) | |
| download | linux-110080cea0d0e4dfdb0b536e7f8a5633ead6a781.tar.xz | |
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>
Diffstat (limited to 'drivers/misc/genwqe/card_utils.c')
| -rw-r--r-- | drivers/misc/genwqe/card_utils.c | 4 |
1 files changed, 4 insertions, 0 deletions
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, |