• Alexey Dobriyan's avatar
    block, zoned: fix integer overflow with BLKRESETZONE et al · 11bde986
    Alexey Dobriyan authored
    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-g359c92c0 #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
    Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
    Signed-off-by: default avatarAlexey Dobriyan (SK hynix) <adobriyan@gmail.com>
    Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
    11bde986
blk-zoned.c 12.3 KB