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 197 at addr 00000000000000c5 by task syz-executor2/27535

CPU: 0 PID: 27535 Comm: syz-executor2 Not tainted 4.17.0-rc3+ #35
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
 do_loop_readv_writev fs/read_write.c:703 [inline]
 do_iter_write+0x491/0x5f0 fs/read_write.c:961
 vfs_writev+0x1c7/0x330 fs/read_write.c:1004
 do_writev+0x112/0x2f0 fs/read_write.c:1039
 __do_sys_writev fs/read_write.c:1112 [inline]
 __se_sys_writev fs/read_write.c:1109 [inline]
 __x64_sys_writev+0x75/0xb0 fs/read_write.c:1109
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455979
RSP: 002b:00007f270eeacc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f270eead6d4 RCX: 0000000000455979
RDX: 0000000000000001 RSI: 0000000020000240 RDI: 0000000000000013
RBP: 000000000072bf50 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000072a R14: 00000000006fec90 R15: 0000000000000001
==================================================================