Got this at a 32 bit KVM during boot :
Apr 14 15:40:24 n22kvm-clone kernel: ================================================================================
Apr 14 15:40:24 n22kvm-clone kernel: UBSAN: Undefined behaviour in ./arch/x86/include/asm/atomic.h:156:2
Apr 14 15:40:24 n22kvm-clone kernel: signed integer overflow:
Apr 14 15:40:24 n22kvm-clone kernel: -1734152656 + -1656360868 cannot be represented in type 'int'
Apr 14 15:40:24 n22kvm-clone kernel: CPU: 0 PID: 2393 Comm: ntpd Not tainted 4.6.0-rc3 #5
Apr 14 15:40:24 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 15:40:24 n22kvm-clone kernel: 00000000 00200086 f3d2da90 d6fe2fe8 00000007 f3d2dac0 9d45f05c f3d2daa0
Apr 14 15:40:24 n22kvm-clone kernel: d704887e f3d2daa0 d7d6bc6c f3d2db24 d7048bcb d7748588 f3d2dac4 0000002b
Apr 14 15:40:24 n22kvm-clone kernel: f3d2daec d7d6bc6c 0000002b 00200286 3337312d 32353134 00363536 00000027
Apr 14 15:40:24 n22kvm-clone kernel: Call Trace:
Apr 14 15:40:24 n22kvm-clone kernel: [<d6fe2fe8>] dump_stack+0x9f/0xe7
Apr 14 15:40:24 n22kvm-clone kernel: [<d704887e>] ubsan_epilogue+0xe/0x40
Apr 14 15:40:24 n22kvm-clone kernel: [<d7048bcb>] handle_overflow+0xbb/0xf0
Apr 14 15:40:24 n22kvm-clone kernel: [<d70082d0>] ? copy_from_iter+0xc0/0x740
Apr 14 15:40:24 n22kvm-clone kernel: [<d73f9dec>] ? ip_generic_getfrag+0x8c/0xf0
Apr 14 15:40:24 n22kvm-clone kernel: [<d7048c12>] __ubsan_handle_add_overflow+0x12/0x20
Apr 14 15:40:24 n22kvm-clone kernel: [<d73deda9>] ip_idents_reserve+0x79/0xa0
Apr 14 15:40:24 n22kvm-clone kernel: [<d73e0eff>] __ip_select_ident+0xaf/0x150
Apr 14 15:40:24 n22kvm-clone kernel: [<d740338f>] __ip_make_skb+0x7bf/0x1200
Apr 14 15:40:24 n22kvm-clone kernel: [<d7404108>] ip_make_skb+0xd8/0x100
Apr 14 15:40:24 n22kvm-clone kernel: [<d73f9d60>] ? ip_reply_glue_bits+0x90/0x90
Apr 14 15:40:24 n22kvm-clone kernel: [<d73f9d60>] ? ip_reply_glue_bits+0x90/0x90
Apr 14 15:40:24 n22kvm-clone kernel: [<d733bfc0>] ? sock_recv_errqueue+0x300/0x300
Apr 14 15:40:24 n22kvm-clone kernel: [<d747bd7d>] udp_sendmsg+0x62d/0x15f0
Apr 14 15:40:24 n22kvm-clone kernel: [<d73f9d60>] ? ip_reply_glue_bits+0x90/0x90
Apr 14 15:40:24 n22kvm-clone kernel: [<d6d3c437>] ? rw_copy_check_uvector+0x67/0x1c0
Apr 14 15:40:24 n22kvm-clone kernel: [<d6b2f4a6>] ? __lock_is_held+0x36/0x90
Apr 14 15:40:24 n22kvm-clone kernel: [<d749b096>] ? inet_sendmsg+0x106/0x350
Apr 14 15:40:24 n22kvm-clone kernel: [<d749b100>] inet_sendmsg+0x170/0x350
Apr 14 15:40:24 n22kvm-clone kernel: [<d749afb9>] ? inet_sendmsg+0x29/0x350
Apr 14 15:40:24 n22kvm-clone kernel: [<d749af90>] ? ipip_gro_complete+0xa0/0xa0
Apr 14 15:40:24 n22kvm-clone kernel: [<d7334239>] ___sys_sendmsg+0x289/0x6a0
Apr 14 15:40:24 n22kvm-clone kernel: [<d6b2f4a6>] ? __lock_is_held+0x36/0x90
Apr 14 15:40:24 n22kvm-clone kernel: [<d6d79070>] ? __fget+0x190/0x350
Apr 14 15:40:24 n22kvm-clone kernel: [<d6d79084>] ? __fget+0x1a4/0x350
Apr 14 15:40:24 n22kvm-clone kernel: [<d6d78f03>] ? __fget+0x23/0x350
Apr 14 15:40:24 n22kvm-clone kernel: [<d6d792b2>] ? __fget_light+0x42/0x170
Apr 14 15:40:24 n22kvm-clone kernel: [<d6d793f2>] ? __fdget+0x12/0x20
Apr 14 15:40:24 n22kvm-clone kernel: [<d7330f38>] ? sockfd_lookup_light+0x18/0xe0
Apr 14 15:40:24 n22kvm-clone kernel: [<d7335380>] __sys_sendmmsg+0xf0/0x1d0
Apr 14 15:40:24 n22kvm-clone kernel: [<d6a85ab7>] ? kvm_clock_get_cycles+0x17/0x20
Apr 14 15:40:24 n22kvm-clone kernel: [<d6b85ba2>] ? __getnstimeofday64+0x102/0x460
Apr 14 15:40:24 n22kvm-clone kernel: [<d6b85f0d>] ? getnstimeofday64+0xd/0x30
Apr 14 15:40:24 n22kvm-clone kernel: [<d6cf1855>] ? remove_vma+0x75/0x100
Apr 14 15:40:24 n22kvm-clone kernel: [<d6cf7745>] ? vm_munmap+0x45/0x70
Apr 14 15:40:24 n22kvm-clone kernel: [<d6a032ae>] ? do_fast_syscall_32+0x4e/0x960
Apr 14 15:40:24 n22kvm-clone kernel: [<d733547f>] SyS_sendmmsg+0x1f/0x30
Apr 14 15:40:24 n22kvm-clone kernel: [<d6a033b0>] do_fast_syscall_32+0x150/0x960
Apr 14 15:40:24 n22kvm-clone kernel: [<d7335460>] ? __sys_sendmmsg+0x1d0/0x1d0
Apr 14 15:40:24 n22kvm-clone kernel: [<d75bfeeb>] sysenter_past_esp+0x4c/0x7f
Apr 14 15:40:24 n22kvm-clone kernel: ================================================================================
--
Toralf
PGP: C4EACDDE 0076E94E, OTR: 420E74C8 30246EE7
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