bisecting fixing commit since cb95712138ec5e480db5160b41172bbc6f6494cc building syzkaller on cef5ae6814696260ff58c538a1b6044af90c5979 testing commit cb95712138ec5e480db5160b41172bbc6f6494cc with gcc (GCC) 8.1.0 kernel signature: 7a4b93d09ef4dddcdf5cff9c7ff4edf0302edfadbd47dfba7be0cd107b48dabe run #0: crashed: INFO: trying to register non-static key in l2cap_chan_del run #1: crashed: INFO: trying to register non-static key in l2cap_chan_del run #2: crashed: INFO: trying to register non-static key in l2cap_chan_del run #3: crashed: INFO: trying to register non-static key in l2cap_chan_del run #4: crashed: INFO: trying to register non-static key in l2cap_chan_del run #5: crashed: INFO: trying to register non-static key in l2cap_chan_del run #6: crashed: INFO: trying to register non-static key in l2cap_chan_del run #7: crashed: INFO: trying to register non-static key in l2cap_chan_del run #8: crashed: WARNING: locking bug in l2cap_chan_del run #9: crashed: INFO: trying to register non-static key in l2cap_chan_del testing current HEAD 865c50e1d279671728c2936cb7680eb89355eeea testing commit 865c50e1d279671728c2936cb7680eb89355eeea with gcc (GCC) 8.1.0 kernel signature: 0285bb6095b8f93ce99a90a0c055f7afb6f2b589d2d825a29d9d97ba2130a983 run #0: crashed: INFO: trying to register non-static key in l2cap_chan_del run #1: crashed: WARNING: locking bug in l2cap_chan_del run #2: crashed: WARNING: locking bug in l2cap_chan_del run #3: crashed: INFO: trying to register non-static key in l2cap_chan_del run #4: crashed: INFO: trying to register non-static key in l2cap_chan_del run #5: crashed: WARNING: locking bug in l2cap_chan_del run #6: crashed: WARNING: locking bug in l2cap_chan_del run #7: crashed: INFO: trying to register non-static key in l2cap_chan_del run #8: crashed: WARNING: refcount bug in l2cap_sock_kill run #9: crashed: INFO: trying to register non-static key in l2cap_chan_del revisions tested: 2, total time: 17m11.02341732s (build: 9m25.159709242s, test: 7m19.023976871s) the crash still happens on HEAD commit msg: x86/uaccess: utilize CONFIG_CC_HAS_ASM_GOTO_OUTPUT crash: INFO: trying to register non-static key in l2cap_chan_del INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 0 PID: 6848 Comm: kworker/0:3 Not tainted 5.9.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events l2cap_chan_timeout Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xa3/0xc8 lib/dump_stack.c:118 assign_lock_key kernel/locking/lockdep.c:933 [inline] register_lock_class+0x575/0x580 kernel/locking/lockdep.c:1245 __lock_acquire+0x75/0x1770 kernel/locking/lockdep.c:4716 lock_acquire+0xf9/0x420 kernel/locking/lockdep.c:5442 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175 spin_lock_bh include/linux/spinlock.h:359 [inline] lock_sock_nested+0x2c/0x90 net/core/sock.c:3048 l2cap_sock_teardown_cb+0x20/0x160 net/bluetooth/l2cap_sock.c:1520 l2cap_chan_del+0x35/0x320 net/bluetooth/l2cap_core.c:618 l2cap_chan_close+0xfb/0x270 net/bluetooth/l2cap_core.c:823 l2cap_chan_timeout+0x70/0xe0 net/bluetooth/l2cap_core.c:436 process_one_work+0x273/0x600 kernel/workqueue.c:2269 worker_thread+0x38/0x380 kernel/workqueue.c:2415 kthread+0x148/0x170 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 0 P4D 0 Oops: 0010 [#1] PREEMPT SMP CPU: 0 PID: 6848 Comm: kworker/0:3 Not tainted 5.9.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events l2cap_chan_timeout RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffffc90000e37d88 EFLAGS: 00010246 RAX: 0000000000000005 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000001 RSI: ffffffff840abdb6 RDI: ffff88810f8a9000 RBP: ffff88810f8a9000 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000001aa40 R11: 0000000000000000 R12: 000000000000006f R13: ffff88810e117800 R14: 0000000000000000 R15: ffff88810e117918 FS: 0000000000000000(0000) GS:ffff88812c000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000123737000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: l2cap_sock_teardown_cb+0x143/0x160 net/bluetooth/l2cap_sock.c:1547 l2cap_chan_del+0x35/0x320 net/bluetooth/l2cap_core.c:618 l2cap_chan_close+0xfb/0x270 net/bluetooth/l2cap_core.c:823 l2cap_chan_timeout+0x70/0xe0 net/bluetooth/l2cap_core.c:436 process_one_work+0x273/0x600 kernel/workqueue.c:2269 worker_thread+0x38/0x380 kernel/workqueue.c:2415 kthread+0x148/0x170 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Modules linked in: CR2: 0000000000000000 ---[ end trace adb7cb1a2a48bfb7 ]--- RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffffc90000e37d88 EFLAGS: 00010246 RAX: 0000000000000005 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000001 RSI: ffffffff840abdb6 RDI: ffff88810f8a9000 RBP: ffff88810f8a9000 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000001aa40 R11: 0000000000000000 R12: 000000000000006f R13: ffff88810e117800 R14: 0000000000000000 R15: ffff88810e117918 FS: 0000000000000000(0000) GS:ffff88812c000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000123737000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400