bisecting fixing commit since 13d2ce42de8cb98ff952f8de6307f896203854c2 building syzkaller on 821e0b09046a2f972ace26fbdc02aef1116792d4 testing commit 13d2ce42de8cb98ff952f8de6307f896203854c2 with gcc (GCC) 8.4.1 20210217 kernel signature: 04503a64a897fefeb2ba8d2468f79f63dd65abe2ae9e544239670d3c5816c1ce run #0: crashed: BUG: corrupted list in kobject_add_internal run #1: crashed: BUG: corrupted list in kobject_add_internal run #2: crashed: BUG: corrupted list in kobject_add_internal run #3: crashed: BUG: corrupted list in kobject_add_internal run #4: crashed: BUG: corrupted list in kobject_add_internal run #5: crashed: BUG: corrupted list in kobject_add_internal run #6: crashed: BUG: corrupted list in kobject_add_internal run #7: crashed: BUG: corrupted list in kobject_add_internal run #8: crashed: BUG: corrupted list in kobject_add_internal run #9: crashed: BUG: corrupted list in kobject_add_internal run #10: crashed: BUG: corrupted list in kobject_add_internal run #11: crashed: BUG: corrupted list in kobject_add_internal run #12: crashed: BUG: corrupted list in kobject_add_internal run #13: crashed: BUG: corrupted list in kobject_add_internal run #14: crashed: BUG: corrupted list in kobject_add_internal run #15: crashed: BUG: corrupted list in kobject_add_internal run #16: crashed: BUG: corrupted list in kobject_add_internal run #17: crashed: kernel panic: Fatal exception run #18: crashed: kernel panic: Fatal exception run #19: crashed: general protection fault in klist_next testing current HEAD 9f84340f012ee60c12aacc03662bcdd67419a31a testing commit 9f84340f012ee60c12aacc03662bcdd67419a31a with gcc (GCC) 8.4.1 20210217 kernel signature: 6d767fcdec863b55cd64fcadd72005533a59ef1e3543df574dc380372cd04648 run #0: crashed: BUG: corrupted list in kobject_add_internal run #1: crashed: BUG: corrupted list in kobject_add_internal run #2: crashed: BUG: corrupted list in kobject_add_internal run #3: crashed: BUG: corrupted list in kobject_add_internal run #4: crashed: BUG: corrupted list in kobject_add_internal run #5: crashed: BUG: corrupted list in kobject_add_internal run #6: crashed: BUG: corrupted list in kobject_add_internal run #7: crashed: BUG: corrupted list in kobject_add_internal run #8: crashed: general protection fault in klist_next run #9: crashed: general protection fault in klist_next revisions tested: 2, total time: 34m5.796988378s (build: 15m36.649229552s, test: 18m5.815296633s) the crash still happens on HEAD commit msg: Linux 4.19.196 crash: general protection fault in klist_next ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 kobject_add_internal failed for hci5:0 with -EEXIST, don't try to register things with the same name in the same directory. Bluetooth: hci5: failed to register connection device kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 31509 Comm: syz-executor.3 Not tainted 4.19.196-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:klist_next+0x48/0x450 lib/klist.c:378 Code: 48 89 fb 48 83 ec 18 80 3c 02 00 0f 85 e1 02 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 23 49 8d 7c 24 50 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 b4 02 00 00 4c 8d 6b 08 4d 8b 7c 24 50 48 b8 00 RSP: 0018:ffff8880b361f698 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: ffff8880b361f718 RCX: ffffffff87a3e038 RDX: 000000000000000a RSI: ffff8880b361f718 RDI: 0000000000000050 RBP: ffff8880b361f6d8 R08: fffffbfff13301ea R09: fffffbfff13301e9 R10: fffffbfff13301e9 R11: ffffffff89980f4f R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff86d8c400 R15: dffffc0000000000 FS: 00007fb4d87cd700(0000) GS:ffff8880ba300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055ca0115e980 CR3: 000000009c232000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: next_device drivers/base/core.c:2397 [inline] device_find_child+0xb1/0x170 drivers/base/core.c:2540 hci_conn_del_sysfs+0xaa/0x150 net/bluetooth/hci_sysfs.c:71 hci_conn_cleanup+0x1ff/0x4e0 net/bluetooth/hci_conn.c:128 hci_conn_del+0x22c/0x6b0 net/bluetooth/hci_conn.c:611 hci_conn_hash_flush+0x171/0x230 net/bluetooth/hci_conn.c:1513 hci_dev_do_close+0x57e/0xe10 net/bluetooth/hci_core.c:1673 hci_unregister_dev+0x167/0x890 net/bluetooth/hci_core.c:3278 vhci_release+0x6b/0xe0 drivers/bluetooth/hci_vhci.c:354 __fput+0x249/0x7f0 fs/file_table.c:278 ____fput+0x9/0x10 fs/file_table.c:309 task_work_run+0x108/0x180 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xa6a/0x2d90 kernel/exit.c:870 do_group_exit+0xf8/0x2c0 kernel/exit.c:967 get_signal+0x30b/0x1970 kernel/signal.c:2589 do_signal+0x87/0x1870 arch/x86/kernel/signal.c:799 exit_to_usermode_loop+0x159/0x1e0 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x413/0x4e0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465af9 Code: Bad RIP value. RSP: 002b:00007fb4d87cd188 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: fffffffffffffff0 RBX: 000000000056bf60 RCX: 0000000000465af9 RDX: 0000000000000008 RSI: 0000000020000140 RDI: 0000000000000004 RBP: 00000000004b0682 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007fffc9757c3f R14: 00007fb4d87cd300 R15: 0000000000022000 Modules linked in: ---[ end trace dc57e154fa8322e6 ]--- RIP: 0010:klist_next+0x48/0x450 lib/klist.c:378 Code: 48 89 fb 48 83 ec 18 80 3c 02 00 0f 85 e1 02 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 23 49 8d 7c 24 50 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 b4 02 00 00 4c 8d 6b 08 4d 8b 7c 24 50 48 b8 00 RSP: 0018:ffff8880b361f698 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: ffff8880b361f718 RCX: ffffffff87a3e038 RDX: 000000000000000a RSI: ffff8880b361f718 RDI: 0000000000000050 RBP: ffff8880b361f6d8 R08: fffffbfff13301ea R09: fffffbfff13301e9 R10: fffffbfff13301e9 R11: ffffffff89980f4f R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff86d8c400 R15: dffffc0000000000 FS: 00007fb4d87cd700(0000) GS:ffff8880ba300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000465acf CR3: 000000009c232000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400