Restarting kernel threads ... done.
Restarting kernel threads ... done.
==================================================================
BUG: KASAN: null-ptr-deref in _copy_from_user+0x100/0x150 lib/usercopy.c:12
Write of size 192 at addr 00000000000000c0 by task syz-executor4/10152

CPU: 1 PID: 10152 Comm: syz-executor4 Not tainted 4.17.0-rc3+ #36
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 kasan_report_error mm/kasan/report.c:352 [inline]
 kasan_report.cold.7+0x6d/0x2fe mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
 kasan_check_write+0x14/0x20 mm/kasan/kasan.c:278
 _copy_from_user+0x100/0x150 lib/usercopy.c:12
 copy_from_user include/linux/uaccess.h:147 [inline]
 simple_write_to_buffer+0xaf/0x130 fs/libfs.c:669
 snapshot_write+0x16d/0x270 kernel/power/user.c:189
 __vfs_write+0x10b/0x960 fs/read_write.c:485
 vfs_write+0x1f8/0x560 fs/read_write.c:549
 ksys_write+0xf9/0x250 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455979
RSP: 002b:00007f8273571c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f82735726d4 RCX: 0000000000455979
RDX: 00000000000000c0 RSI: 00000000200000c0 RDI: 0000000000000013
RBP: 000000000072c000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000727 R14: 00000000006fec48 R15: 0000000000000002
==================================================================