On 2/12/20 10:40 AM, Alexey Dobriyan wrote:
> Check for overflow in addition before checking for end-of-block-device.
>
> Steps to reproduce:
>
> #define _GNU_SOURCE 1
> #include <sys/ioctl.h>
> #include <sys/types.h>
> #include <sys/stat.h>
> #include <fcntl.h>
>
> typedef unsigned long long __u64;
>
> struct blk_zone_range {
> __u64 sector;
> __u64 nr_sectors;
> };
>
> #define BLKRESETZONE _IOW(0x12, 131, struct blk_zone_range)
>
> int main(void)
> {
> int fd = open("/dev/nullb0", O_RDWR|O_DIRECT);
> struct blk_zone_range zr = {4096, 0xfffffffffffff000ULL};
> ioctl(fd, BLKRESETZONE, &zr);
> return 0;
> }
>
> BUG: KASAN: null-ptr-deref in submit_bio_wait+0x74/0xe0
> Write of size 8 at addr 0000000000000040 by task a.out/1590
>
> CPU: 8 PID: 1590 Comm: a.out Not tainted 5.6.0-rc1-00019-g359c92c02bfa #2
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190711_202441-buildvm-armv7-10.arm.fedoraproject.org-2.fc31 04/01/2014
> Call Trace:
> dump_stack+0x76/0xa0
> __kasan_report.cold+0x5/0x3e
> kasan_report+0xe/0x20
> submit_bio_wait+0x74/0xe0
> blkdev_zone_mgmt+0x26f/0x2a0
> blkdev_zone_mgmt_ioctl+0x14b/0x1b0
> blkdev_ioctl+0xb28/0xe60
> block_ioctl+0x69/0x80
> ksys_ioctl+0x3af/0xa50
Applied, thanks.
--
Jens Axboe
