From: Alexey Dobriyan <adobriyan@xxxxxxxxx> [ Upstream commit 11bde986002c0af67eb92d73321d06baefae7128 ] 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 Reviewed-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Alexey Dobriyan (SK hynix) <adobriyan@xxxxxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- block/blk-zoned.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/blk-zoned.c b/block/blk-zoned.c index 05741c6f618be..6b442ae96499a 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -173,7 +173,7 @@ int blkdev_zone_mgmt(struct block_device *bdev, enum req_opf op, if (!op_is_zone_mgmt(op)) return -EOPNOTSUPP; - if (!nr_sectors || end_sector > capacity) + if (end_sector <= sector || end_sector > capacity) /* Out of range */ return -EINVAL; -- 2.20.1