bisecting cause commit starting from fd1f297b794c77e52412dc621b5884210291eeee building syzkaller on 3361bde5773da39c293045c578c844ddc89291e6 testing commit fd1f297b794c77e52412dc621b5884210291eeee with gcc (GCC) 8.1.0 run #0: crashed: WARNING in arch_install_hw_breakpoint run #1: crashed: WARNING in arch_install_hw_breakpoint run #2: crashed: WARNING in arch_install_hw_breakpoint run #3: crashed: WARNING in arch_install_hw_breakpoint run #4: crashed: WARNING in arch_install_hw_breakpoint run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK testing release v5.0 testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.1.0 all runs: crashed: WARNING in arch_install_hw_breakpoint testing release v4.20 testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.1.0 all runs: crashed: WARNING in arch_install_hw_breakpoint testing release v4.19 testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.1.0 all runs: crashed: WARNING in arch_install_hw_breakpoint testing release v4.18 testing commit 94710cac0ef4ee177a63b5227664b38c95bbf703 with gcc (GCC) 8.1.0 all runs: crashed: WARNING in arch_install_hw_breakpoint testing release v4.17 testing commit 29dcea88779c856c7dc92040a0c01233263101d4 with gcc (GCC) 8.1.0 run #0: crashed: WARNING in arch_install_hw_breakpoint run #1: OK run #2: OK run #3: crashed: WARNING in arch_install_hw_breakpoint run #4: crashed: WARNING in arch_install_hw_breakpoint run #5: crashed: WARNING in arch_install_hw_breakpoint run #6: crashed: WARNING in arch_install_hw_breakpoint run #7: crashed: WARNING in arch_install_hw_breakpoint run #8: crashed: WARNING in arch_install_hw_breakpoint run #9: crashed: WARNING in arch_install_hw_breakpoint testing release v4.16 testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.1.0 all runs: crashed: WARNING in arch_install_hw_breakpoint testing release v4.15 testing commit d8a5b80568a9cb66810e75b182018e9edb68e8ff with gcc (GCC) 8.1.0 all runs: crashed: WARNING in arch_install_hw_breakpoint testing release v4.14 testing commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 with gcc (GCC) 8.1.0 all runs: crashed: WARNING in arch_install_hw_breakpoint testing release v4.13 testing commit 569dbb88e80deb68974ef6fdd6a13edb9d686261 with gcc (GCC) 8.1.0 all runs: crashed: WARNING in arch_install_hw_breakpoint testing release v4.12 testing commit 6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c with gcc (GCC) 8.1.0 all runs: crashed: WARNING in arch_install_hw_breakpoint testing release v4.11 testing commit a351e9b9fc24e982ec2f0e76379a49826036da12 with gcc (GCC) 7.3.0 all runs: crashed: WARNING in arch_install_hw_breakpoint testing release v4.10 testing commit c470abd4fde40ea6a0846a2beab642a578c0b8cd with gcc (GCC) 5.5.0 all runs: crashed: WARNING in arch_install_hw_breakpoint testing release v4.9 testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0 all runs: crashed: WARNING in arch_install_hw_breakpoint testing release v4.8 testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0 all runs: crashed: WARNING in arch_install_hw_breakpoint testing release v4.7 testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0 all runs: crashed: possible deadlock in copy_cgroup_ns testing release v4.6 testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0 run #0: crashed: WARNING in arch_install_hw_breakpoint run #1: OK run #2: OK run #3: crashed: WARNING in arch_install_hw_breakpoint run #4: crashed: WARNING in arch_install_hw_breakpoint run #5: crashed: WARNING in arch_install_hw_breakpoint run #6: crashed: WARNING in arch_install_hw_breakpoint run #7: crashed: WARNING in arch_install_hw_breakpoint run #8: crashed: WARNING in arch_install_hw_breakpoint run #9: crashed: INFO: task hung in copy_process testing release v4.5 testing commit b562e44f507e863c6792946e4e1b1449fbbac85d with gcc (GCC) 5.5.0 all runs: crashed: WARNING in arch_install_hw_breakpoint testing release v4.4 testing commit afd2ff9b7e1b367172f18ba7f693dfb62bdcb2dc with gcc (GCC) 5.5.0 all runs: crashed: WARNING in arch_install_hw_breakpoint testing release v4.3 testing commit 6a13feb9c82803e2b815eca72fa7a9f5561d7861 with gcc (GCC) 5.5.0 run #0: crashed: WARNING in arch_install_hw_breakpoint run #1: OK run #2: crashed: WARNING in arch_install_hw_breakpoint run #3: crashed: WARNING in arch_install_hw_breakpoint run #4: crashed: WARNING in arch_install_hw_breakpoint run #5: crashed: WARNING in arch_install_hw_breakpoint run #6: crashed: WARNING in arch_install_hw_breakpoint run #7: crashed: WARNING in arch_install_hw_breakpoint run #8: crashed: WARNING in arch_install_hw_breakpoint run #9: crashed: WARNING in arch_install_hw_breakpoint testing release v4.2 testing commit 64291f7db5bd8150a74ad2036f1037e6a0428df2 with gcc (GCC) 5.5.0 all runs: crashed: WARNING in arch_install_hw_breakpoint testing release v4.1 testing commit b953c0d234bc72e8489d3bf51a276c5c4ec85345 with gcc (GCC) 5.5.0 all runs: crashed: WARNING in arch_install_hw_breakpoint revisions tested: 22, total time: 2h45m25.049769023s (build: 1h20m7.884286787s, test: 1h20m43.288341779s) the crash already happened on the oldest tested release crash: WARNING in arch_install_hw_breakpoint bridge0: port 2(bridge_slave_1) entered forwarding state bridge0: port 1(bridge_slave_0) entered forwarding state bridge0: port 2(bridge_slave_1) entered forwarding state ------------[ cut here ]------------ WARNING: CPU: 0 PID: 8691 at arch/x86/kernel/hw_breakpoint.c:119 arch_install_hw_breakpoint+0x152/0x160 arch/x86/kernel/hw_breakpoint.c:119() Can't find any breakpoint slot Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 8691 Comm: syz-executor.1 Not tainted 4.1.0 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 ffffffff82e1da08 ffff880073fe7968 ffffffff8263933b 0000000000000032 ffffffff82e3161b ffff880073fe79e8 ffffffff826351ce 0000000000000000 ffffffff00000008 ffff880073fe79f8 ffff880073fe7998 ffff880073fe79c8 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0x4f/0x7b lib/dump_stack.c:50 [] panic+0xcd/0x211 kernel/panic.c:111 [] warn_slowpath_common+0xbb/0xc0 kernel/panic.c:442 [] warn_slowpath_fmt+0x41/0x50 kernel/panic.c:458 [] arch_install_hw_breakpoint+0x152/0x160 arch/x86/kernel/hw_breakpoint.c:119 [] hw_breakpoint_add+0x43/0x50 kernel/events/hw_breakpoint.c:590 [] event_sched_in.isra.86+0xe6/0x300 kernel/events/core.c:1895 [] group_sched_in+0x66/0x1e0 kernel/events/core.c:1936 [] ctx_flexible_sched_in kernel/events/core.c:2750 [inline] [] ctx_sched_in+0x1e0/0x470 kernel/events/core.c:2781 [] perf_event_sched_in+0x64/0x90 kernel/events/core.c:2049 [] perf_event_context_sched_in+0x92/0x160 kernel/events/core.c:2814 [] __perf_event_task_sched_in+0x138/0x1f0 kernel/events/core.c:2842 [] perf_event_task_sched_in include/linux/perf_event.h:801 [inline] [] finish_task_switch+0xe8/0x130 kernel/sched/core.c:2229 [] context_switch kernel/sched/core.c:2340 [inline] [] __schedule+0x36c/0x9e0 kernel/sched/core.c:2798 [] schedule+0x32/0x80 kernel/sched/core.c:2826 [] freezable_schedule include/linux/freezer.h:171 [inline] [] ptrace_stop+0x17d/0x300 kernel/signal.c:1909 [] do_jobctl_trap kernel/signal.c:2128 [inline] [] get_signal+0x5f8/0xa30 kernel/signal.c:2246 [] do_signal+0x23/0xb10 arch/x86/kernel/signal.c:690 [] do_notify_resume+0x58/0x70 arch/x86/kernel/signal.c:735 [] int_signal+0x12/0x17 Shutting down cpus with NMI Kernel Offset: disabled drm_kms_helper: panic occurred, switching back to text console