Toralf Förster: > Got this at a 32 bit KVM during boot : and later while fuzzying with trinity :
Apr 14 15:44:56 n22kvm-clone kernel: ================================================================================ Apr 14 15:44:56 n22kvm-clone kernel: UBSAN: Undefined behaviour in ./arch/x86/include/asm/futex.h:53:13 Apr 14 15:44:56 n22kvm-clone kernel: shift exponent -1 is negative Apr 14 15:44:56 n22kvm-clone kernel: CPU: 0 PID: 13969 Comm: trinity-c1 Not tainted 4.6.0-rc3 #5 Apr 14 15:44:56 n22kvm-clone kernel: Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.2-0-g33fbe13 by qemu-project.org 04/01/2014 Apr 14 15:44:56 n22kvm-clone kernel: 00000000 00000086 f3e7fde8 d6fe2fe8 00000007 f3e7fe14 d78b8dac f3e7fdf8 Apr 14 15:44:56 n22kvm-clone kernel: d704887e f3e7fdf8 d78b8dac f3e7fe78 d704919d d774876c f3e7fe18 00000002 Apr 14 15:44:56 n22kvm-clone kernel: f3e16180 00000001 00000286 d600312d f3e7fe5c 00000286 00000000 00000001 Apr 14 15:44:56 n22kvm-clone kernel: Call Trace: Apr 14 15:44:56 n22kvm-clone kernel: [<d6fe2fe8>] dump_stack+0x9f/0xe7 Apr 14 15:44:56 n22kvm-clone kernel: [<d704887e>] ubsan_epilogue+0xe/0x40 Apr 14 15:44:56 n22kvm-clone kernel: [<d704919d>] __ubsan_handle_shift_out_of_bounds+0xdd/0x140 Apr 14 15:44:56 n22kvm-clone kernel: [<d6ba2257>] ? do_futex+0x257/0xdc0 Apr 14 15:44:56 n22kvm-clone kernel: [<d75bf3ad>] ? _raw_spin_lock_nested+0x3d/0x50 Apr 14 15:44:56 n22kvm-clone kernel: [<d6ba2a04>] do_futex+0xa04/0xdc0 Apr 14 15:44:56 n22kvm-clone kernel: [<d75bfb0f>] ? _raw_spin_unlock_irqrestore+0x5f/0x80 Apr 14 15:44:56 n22kvm-clone kernel: [<d6ba2e44>] SyS_futex+0x84/0x150 Apr 14 15:44:56 n22kvm-clone kernel: [<d6a033b0>] do_fast_syscall_32+0x150/0x960 Apr 14 15:44:56 n22kvm-clone kernel: [<d6ba2dc0>] ? do_futex+0xdc0/0xdc0 Apr 14 15:44:56 n22kvm-clone kernel: [<d75bfeeb>] sysenter_past_esp+0x4c/0x7f Apr 14 15:44:56 n22kvm-clone kernel: ================================================================================ -- Toralf PGP: C4EACDDE 0076E94E, OTR: 420E74C8 30246EE7
