------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 7 at lib/refcount.c:25 refcount_warn_saturate+0x13d/0x1a0 lib/refcount.c:25 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 7 Comm: kworker/u4:0 Not tainted 5.9.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: qrtr_ns_handler qrtr_ns_worker Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d6/0x29e lib/dump_stack.c:118 panic+0x2c0/0x800 kernel/panic.c:231 __warn+0x227/0x250 kernel/panic.c:600 report_bug+0x1b1/0x2e0 lib/bug.c:198 handle_bug+0x42/0x80 arch/x86/kernel/traps.c:234 exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:254 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536 RIP: 0010:refcount_warn_saturate+0x13d/0x1a0 lib/refcount.c:25 Code: c7 a3 0c 38 89 31 c0 e8 41 5a 88 fd 0f 0b eb a3 e8 08 bb b6 fd c6 05 c2 4d ed 05 01 48 c7 c7 da 0c 38 89 31 c0 e8 23 5a 88 fd <0f> 0b eb 85 e8 ea ba b6 fd c6 05 a5 4d ed 05 01 48 c7 c7 06 0d 38 RSP: 0018:ffffc90000cdf9c0 EFLAGS: 00010046 RAX: a65b080b5852b000 RBX: 0000000000000002 RCX: ffff8880a99d01c0 RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000 RBP: 0000000000000002 R08: ffffffff815e27c0 R09: ffffed1015d241c3 R10: ffffed1015d241c3 R11: 0000000000000000 R12: ffff8880a8865c98 R13: 1ffff1101507671e R14: 0000000000000282 R15: ffff8880a8865c00 refcount_add include/linux/refcount.h:206 [inline] refcount_inc include/linux/refcount.h:241 [inline] kref_get include/linux/kref.h:45 [inline] qrtr_node_acquire net/qrtr/qrtr.c:196 [inline] qrtr_node_lookup+0xc0/0xd0 net/qrtr/qrtr.c:389 qrtr_send_resume_tx net/qrtr/qrtr.c:981 [inline] qrtr_recvmsg+0x429/0xa80 net/qrtr/qrtr.c:1044 qrtr_ns_worker+0x176/0x45f0 net/qrtr/ns.c:624 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Shutting down cpus with NMI Kernel Offset: disabled Rebooting in 86400 seconds..