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BUG: KMSAN: uninit-value in do_error_trap+0x39b/0x600 arch/x86/kernel/traps.c:297
CPU: 1 PID: 7896 Comm: syz-executor0 Not tainted 4.17.0-rc3+ #88
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+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:683
 do_error_trap+0x39b/0x600 arch/x86/kernel/traps.c:297
 do_invalid_op+0x46/0x50 arch/x86/kernel/traps.c:316
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992
RIP: 0010:kmsan_copy_to_user+0x141/0x160 mm/kmsan/kmsan.c:1213
RSP: 0018:ffff88014830fce0 EFLAGS: 00010202
RAX: ffff88014b70d7c0 RBX: ffff88014830fd90 RCX: 0000000000000008
RDX: 00007ffffffff000 RSI: ffff88014830fd90 RDI: ffffffffffffffff
RBP: ffff88014830fd28 R08: 0000000001080020 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000008
R13: ffffffffffffffff R14: 0000000000000008 R15: 0000000000000000
 copy_to_user include/linux/uaccess.h:184 [inline]
 fcntl_rw_hint fs/fcntl.c:287 [inline]
 do_fcntl+0x1866/0x2210 fs/fcntl.c:427
 __do_sys_fcntl fs/fcntl.c:463 [inline]
 __se_sys_fcntl+0x280/0x390 fs/fcntl.c:448
 __x64_sys_fcntl+0xd8/0x110 fs/fcntl.c:448
 do_syscall_64+0x154/0x220 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x455979
RSP: 002b:00007f83d2f20c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000048
RAX: ffffffffffffffda RBX: 00007f83d2f216d4 RCX: 0000000000455979
RDX: ffffffffffffffff RSI: 000000000000040d RDI: 0000000000000014
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000008b R14: 00000000006f4da8 R15: 0000000000000000

Local variable description: ----timeout.i@do_futex
Variable was created at:
 do_futex+0x165/0x6ad0 kernel/futex.c:3499
 __do_sys_futex kernel/futex.c:3587 [inline]
 __se_sys_futex+0x3fe/0x820 kernel/futex.c:3555
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