xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

genwqe: Prevent an integer overflow in the ioctl

Browse Source 
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: eaf4722d46 ("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>
This commit is contained in:
Dan Carpenter
2019-05-07 11:36:34 +03:00
committed by Greg Kroah-Hartman
parent 1c7ebeabc9
commit 110080cea0
2 changed files with 6 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/misc/genwqe/card_dev.c
View File

@@ -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);