kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
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Modules linked in:
CPU: 3 PID: 985 Comm: syz-executor3 Not tainted 4.13.0-next-20170911+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
task: ffff880038a6e500 task.stack: ffff880027228000
RIP: 0010:loop_set_fd drivers/block/loop.c:885 [inline]
RIP: 0010:lo_ioctl+0x678/0x1b80 drivers/block/loop.c:1353
RSP: 0018:ffff88002722faa0 EFLAGS: 00010202
RAX: 0000000000010000 RBX: dffffc0000000000 RCX: ffffc9000134b000
RDX: 000000000000003b RSI: ffffffff83539218 RDI: 00000000000001d8
RBP: ffff88002722fb18 R08: 0000000000000000 R09: 1ffff10004e45efd
R10: ffff880038a6e500 R11: 0000000000000001 R12: 0000000000000000
R13: ffff88003b7ff6c0 R14: ffff8800696297c0 R15: ffff88003b7ff818
FS:  00007f38c1538700(0000) GS:ffff88006df00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000430cc0 CR3: 000000006810b000 CR4: 00000000000026e0
DR0: 0000000020001000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 __blkdev_driver_ioctl block/ioctl.c:297 [inline]
 blkdev_ioctl+0xc07/0x1de0 block/ioctl.c:594
 block_ioctl+0xea/0x130 fs/block_dev.c:1870
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x447299
RSP: 002b:00007f38c1537c08 EFLAGS: 00000296 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000447299
RDX: 0000000000000016 RSI: 0000000000004c00 RDI: 0000000000000006
RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 00000000ffffffff
R13: 0000000000000590 R14: 00000000006e3650 R15: 0000000000000006
Code: 00 00 00 48 89 fa 48 c1 ea 03 80 3c 1a 00 0f 85 81 14 00 00 4d 8b a4 24 f0 00 00 00 49 8d bc 24 d8 01 00 00 48 89 fa 48 c1 ea 03 <80> 3c 1a 00 0f 85 56 14 00 00 4d 8b a4 24 d8 01 00 00 4c 89 e2 
RIP: loop_set_fd drivers/block/loop.c:885 [inline] RSP: ffff88002722faa0
RIP: lo_ioctl+0x678/0x1b80 drivers/block/loop.c:1353 RSP: ffff88002722faa0
---[ end trace 51b26abc6ca43314 ]---
Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
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Kernel Offset: disabled
Rebooting in 86400 seconds..