bisecting fixing commit since c0842fbc1b18c7a044e6ff3e8fa78bfa822c7d1a building syzkaller on 80a0690249dc4dbbbed95ba197192b99c73694c5 testing commit c0842fbc1b18c7a044e6ff3e8fa78bfa822c7d1a with gcc (GCC) 8.1.0 kernel signature: c43ecf7aa6081f4899eb274c0fac101b708bd51f04bb268b832638af752bc1c1 run #0: crashed: BUG: unable to handle kernel NULL pointer dereference in __queue_work run #1: crashed: WARNING: ODEBUG bug in bt_host_release run #2: crashed: BUG: unable to handle kernel NULL pointer dereference in __queue_work run #3: crashed: BUG: unable to handle kernel NULL pointer dereference in __queue_work run #4: crashed: WARNING: ODEBUG bug in bt_host_release run #5: crashed: WARNING: ODEBUG bug in bt_host_release run #6: crashed: WARNING in __queue_work run #7: OK run #8: OK run #9: OK testing current HEAD e37b12e4bb21e7c81732370b0a2b34bd196f380b testing commit e37b12e4bb21e7c81732370b0a2b34bd196f380b with gcc (GCC) 8.1.0 kernel signature: df0f1249f0f167437fb54b0d13ce95ec0d513cc27763f6659e0bb45b9a956e4a run #0: crashed: BUG: unable to handle kernel NULL pointer dereference in __queue_work run #1: crashed: BUG: unable to handle kernel NULL pointer dereference in __queue_work run #2: crashed: BUG: unable to handle kernel NULL pointer dereference in __queue_work run #3: crashed: BUG: unable to handle kernel NULL pointer dereference in __queue_work run #4: crashed: BUG: unable to handle kernel NULL pointer dereference in __queue_work run #5: crashed: BUG: unable to handle kernel NULL pointer dereference in __queue_work run #6: crashed: BUG: unable to handle kernel NULL pointer dereference in __queue_work run #7: crashed: BUG: unable to handle kernel NULL pointer dereference in __queue_work run #8: OK run #9: crashed: BUG: unable to handle kernel NULL pointer dereference in __queue_work revisions tested: 2, total time: 29m2.238281532s (build: 9m26.899755802s, test: 18m58.12617145s) the crash still happens on HEAD commit msg: Merge tag 'for-linus-5.11-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux crash: BUG: unable to handle kernel NULL pointer dereference in __queue_work BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 1147c4067 P4D 1147c4067 PUD 1166e4067 PMD 0 Oops: 0000 [#1] PREEMPT SMP CPU: 0 PID: 25141 Comm: syz-executor.0 Not tainted 5.10.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__queue_work+0xdc/0x670 kernel/workqueue.c:1440 Code: 88 03 00 00 44 89 ef e8 a2 43 f1 ff 4c 89 e7 89 c6 e8 98 d3 ff ff 48 89 df 49 89 c7 e8 fd dd ff ff 48 85 c0 0f 84 2f 01 00 00 <49> 39 07 0f 85 75 02 00 00 48 89 c7 e8 c3 9c f3 01 41 8b 47 18 85 RSP: 0018:ffffc90000bd3c08 EFLAGS: 00010086 RAX: ffff888101949800 RBX: ffff8881173c4a88 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000005 RDI: ffffffff844f0640 RBP: ffffc90000bd3c40 R08: ffff888100400050 R09: ffff888100400000 R10: 0000000000000000 R11: ffffffff844f0688 R12: ffff88811499e000 R13: 0000000000000000 R14: 0000000000000040 R15: 0000000000000000 FS: 00007f30443ce700(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000116012000 CR4: 0000000000350ef0 Call Trace: queue_work_on+0x99/0xb0 kernel/workqueue.c:1524 queue_work include/linux/workqueue.h:507 [inline] req_run+0xa9/0xf0 net/bluetooth/hci_request.c:87 hci_req_run_skb net/bluetooth/hci_request.c:99 [inline] __hci_req_sync+0xd9/0x280 net/bluetooth/hci_request.c:212 hci_req_sync+0x49/0x70 net/bluetooth/hci_request.c:279 hci_dev_cmd+0x1b2/0x2c0 net/bluetooth/hci_core.c:2026 hci_sock_ioctl+0x1f6/0x3e0 net/bluetooth/hci_sock.c:1052 sock_do_ioctl+0x38/0x130 net/socket.c:1037 sock_ioctl+0x260/0x350 net/socket.c:1177 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x7c/0xb0 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cce9 Code: 2d b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f30443cdc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000001d300 RCX: 000000000045cce9 RDX: 0000000020000000 RSI: 00000000400448de RDI: 0000000000000004 RBP: 000000000078c080 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c04c R13: 00007fffb69831ff R14: 00007f30443ce9c0 R15: 000000000078c04c Modules linked in: CR2: 0000000000000000 ---[ end trace a67e794d84a359cb ]--- RIP: 0010:__queue_work+0xdc/0x670 kernel/workqueue.c:1440 Code: 88 03 00 00 44 89 ef e8 a2 43 f1 ff 4c 89 e7 89 c6 e8 98 d3 ff ff 48 89 df 49 89 c7 e8 fd dd ff ff 48 85 c0 0f 84 2f 01 00 00 <49> 39 07 0f 85 75 02 00 00 48 89 c7 e8 c3 9c f3 01 41 8b 47 18 85 RSP: 0018:ffffc90000bd3c08 EFLAGS: 00010086 RAX: ffff888101949800 RBX: ffff8881173c4a88 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000005 RDI: ffffffff844f0640 RBP: ffffc90000bd3c40 R08: ffff888100400050 R09: ffff888100400000 R10: 0000000000000000 R11: ffffffff844f0688 R12: ffff88811499e000 R13: 0000000000000000 R14: 0000000000000040 R15: 0000000000000000 FS: 00007f30443ce700(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000116012000 CR4: 0000000000350ef0