CPU: 1 PID: 4583 Comm: syz-executor7 Not tainted 4.9.60-gdfe0a9b #81
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801c752fae0 ffffffff81d91389 ffff8801c752fdc0[   67.856552] kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 4617 Comm: syz-executor5 Not tainted 4.9.60-gdfe0a9b #81
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d02bc800 task.stack: ffff8801c8020000
RIP: 0010:[<ffffffff8144db91>] 
 [<ffffffff8144db91>] __read_once_size include/linux/compiler.h:243 [inline]
 [<ffffffff8144db91>] atomic_read arch/x86/include/asm/atomic.h:26 [inline]
 [<ffffffff8144db91>] page_ref_count include/linux/page_ref.h:66 [inline]
 [<ffffffff8144db91>] put_page_testzero include/linux/mm.h:445 [inline]
 [<ffffffff8144db91>] __free_pages+0x21/0x80 mm/page_alloc.c:3901
RSP: 0018:ffff8801c8027ab0  EFLAGS: 00010a07
RAX: dffffc0000000000 RBX: dead4ead00000000 RCX: ffffc9000294f000
RDX: 1bd5a9d5a0000003 RSI: 0000000000000001 RDI: dead4ead0000001c
RBP: ffff8801c8027ac0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000004
R13: 0000000000000020 R14: ffff8801adfec200 R15: dffffc0000000000
FS:  00007f9a30a50700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001bdbc23000 CR3: 00000001d8db7000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801d02bc800
 ffff8801adfec358 ffff8801c8027b20 ffffffff8265fab1[   67.856698]  ffff8801adfec370
 ffffed0035bfd86b ffffed0035bfd86e ffff8801adfec368[   67.856709]  dead4ead00000000
 ffff8801adfec340 0000000000000000 0000000000000000[   67.856718] Call Trace:
 [<ffffffff8265fab1>] sg_remove_scat.isra.20+0x1c1/0x2d0 drivers/scsi/sg.c:1954
 [<ffffffff8265fe75>] sg_finish_rem_req+0x2b5/0x340 drivers/scsi/sg.c:1836
 [<ffffffff8265ff39>] sg_new_read.isra.21+0x39/0x3e0 drivers/scsi/sg.c:567
 [<ffffffff82661b16>] sg_read+0x8a6/0x1400 drivers/scsi/sg.c:456
 [<ffffffff8156c793>] __vfs_read+0x103/0x670 fs/read_write.c:452
 [<ffffffff8156dd27>] vfs_read+0x107/0x330 fs/read_write.c:475
 [<ffffffff815719c9>] SYSC_read fs/read_write.c:591 [inline]
 [<ffffffff815719c9>] SyS_read+0xd9/0x1b0 fs/read_write.c:584
 [<ffffffff838aa305>] entry_SYSCALL_64_fastpath+0x23/0xc6
Code: 
ff 66 0f 1f 84 00 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 e5 53 48 89 fb 48 83 c7 1c 48 89 fa 48 83 ec 08 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 3d [   67.857061] RIP 
 [<ffffffff8144db91>] __read_once_size include/linux/compiler.h:243 [inline]
 [<ffffffff8144db91>] atomic_read arch/x86/include/asm/atomic.h:26 [inline]
 [<ffffffff8144db91>] page_ref_count include/linux/page_ref.h:66 [inline]
 [<ffffffff8144db91>] put_page_testzero include/linux/mm.h:445 [inline]
 [<ffffffff8144db91>] __free_pages+0x21/0x80 mm/page_alloc.c:3901
---[ end trace ac8daa718be55a14 ]---
Kernel panic - not syncing: Fatal exception
 0000000000000000 ffff8801adab4b90 ffff8801c752fcb0 ffff8801adab4a80 ffff8801c752fcd8
 ffffffff8165fc37 0000000000005d9e ffff8801c754a0f0 ffff8801c754a0a0
Call Trace:
 [<ffffffff81d91389>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d91389>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8165fc37>] handle_userfault+0xa37/0x1300 fs/userfaultfd.c:323
 [<ffffffff814cf571>] do_anonymous_page mm/memory.c:2747 [inline]
 [<ffffffff814cf571>] handle_pte_fault mm/memory.c:3488 [inline]
 [<ffffffff814cf571>] __handle_mm_fault mm/memory.c:3577 [inline]
 [<ffffffff814cf571>] handle_mm_fault+0x1fd1/0x2530 mm/memory.c:3614
 [<ffffffff810e0447>] __do_page_fault+0x5b7/0xd70 arch/x86/mm/fault.c:1396
 [<ffffffff810e0c27>] do_page_fault+0x27/0x30 arch/x86/mm/fault.c:1460
 [<ffffffff838ab4d8>] page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1012
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..