projects / thirdparty / kernel / stable-queue.git / blame
| Commit | Line | Data |
|---|---|---|
| 7a7567a2 GKH |
1 | From 110080cea0d0e4dfdb0b536e7f8a5633ead6a781 Mon Sep 17 00:00:00 2001 |
| 2 | From: Dan Carpenter <dan.carpenter@oracle.com> | |
| 3 | Date: Tue, 7 May 2019 11:36:34 +0300 | |
| 4 | Subject: genwqe: Prevent an integer overflow in the ioctl | |
| 5 | ||
| 6 | From: Dan Carpenter <dan.carpenter@oracle.com> | |
| 7 | ||
| 8 | commit 110080cea0d0e4dfdb0b536e7f8a5633ead6a781 upstream. | |
| 9 | ||
| 10 | There are a couple potential integer overflows here. | |
| 11 | ||
| 12 | round_up(m->size + (m->addr & ~PAGE_MASK), PAGE_SIZE); | |
| 13 | ||
| 14 | The first thing is that the "m->size + (...)" addition could overflow, | |
| 15 | and the second is that round_up() overflows to zero if the result is | |
| 16 | within PAGE_SIZE of the type max. | |
| 17 | ||
| 18 | In this code, the "m->size" variable is an u64 but we're saving the | |
| 19 | result in "map_size" which is an unsigned long and genwqe_user_vmap() | |
| 20 | takes an unsigned long as well. So I have used ULONG_MAX as the upper | |
| 21 | bound. From a practical perspective unsigned long is fine/better than | |
| 22 | trying to change all the types to u64. | |
| 23 | ||
| 24 | Fixes: eaf4722d4645 ("GenWQE Character device and DDCB queue") | |
| 25 | Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> | |
| 26 | Cc: stable <stable@vger.kernel.org> | |
| 27 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
| 28 | ||
| 29 | --- | |
| 30 | drivers/misc/genwqe/card_dev.c | 2 ++ | |
| 31 | drivers/misc/genwqe/card_utils.c | 4 ++++ | |
| 32 | 2 files changed, 6 insertions(+) | |
| 33 | ||
| 34 | --- a/drivers/misc/genwqe/card_dev.c | |
| 35 | +++ b/drivers/misc/genwqe/card_dev.c | |
| 36 | @@ -780,6 +780,8 @@ static int genwqe_pin_mem(struct genwqe_ | |
| 37 | ||
| 38 | if ((m->addr == 0x0) || (m->size == 0)) | |
| 39 | return -EINVAL; | |
| 40 | + if (m->size > ULONG_MAX - PAGE_SIZE - (m->addr & ~PAGE_MASK)) | |
| 41 | + return -EINVAL; | |
| 42 | ||
| 43 | map_addr = (m->addr & PAGE_MASK); | |
| 44 | map_size = round_up(m->size + (m->addr & ~PAGE_MASK), PAGE_SIZE); | |
| 45 | --- a/drivers/misc/genwqe/card_utils.c | |
| 46 | +++ b/drivers/misc/genwqe/card_utils.c | |
| 47 | @@ -586,6 +586,10 @@ int genwqe_user_vmap(struct genwqe_dev * | |
| 48 | /* determine space needed for page_list. */ | |
| 49 | data = (unsigned long)uaddr; | |
| 50 | offs = offset_in_page(data); | |
| 51 | + if (size > ULONG_MAX - PAGE_SIZE - offs) { | |
| 52 | + m->size = 0; /* mark unused and not added */ | |
| 53 | + return -EINVAL; | |
| 54 | + } | |
| 55 | m->nr_pages = DIV_ROUND_UP(offs + size, PAGE_SIZE); | |
| 56 | ||
| 57 | m->page_list = kcalloc(m->nr_pages, |