netlink: 8 bytes leftover after parsing attributes in process `syz-executor.1'. ============================================ WARNING: possible recursive locking detected 4.19.204-syzkaller #0 Not tainted -------------------------------------------- syz-executor.0/29405 is trying to acquire lock: 000000008f8a875c (qp_broker_list.mutex){+.+.}, at: vmci_qp_broker_detach+0x147/0x11b0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2099 but task is already holding lock: 000000008f8a875c (qp_broker_list.mutex){+.+.}, at: vmci_qp_broker_detach+0x147/0x11b0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2099 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(qp_broker_list.mutex); lock(qp_broker_list.mutex); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by syz-executor.0/29405: #0: 000000008f8a875c (qp_broker_list.mutex){+.+.}, at: vmci_qp_broker_detach+0x147/0x11b0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2099 stack backtrace: CPU: 1 PID: 29405 Comm: syz-executor.0 Not tainted 4.19.204-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_deadlock_bug kernel/locking/lockdep.c:1764 [inline] check_deadlock kernel/locking/lockdep.c:1808 [inline] validate_chain kernel/locking/lockdep.c:2404 [inline] __lock_acquire.cold+0x121/0x57e kernel/locking/lockdep.c:3416 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 __mutex_lock_common kernel/locking/mutex.c:938 [inline] __mutex_lock+0xd7/0x1200 kernel/locking/mutex.c:1083 vmci_qp_broker_detach+0x147/0x11b0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2099 audit: type=1800 audit(1629115178.281:309): pid=29407 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed comm="syz-executor.2" name="bus" dev="sda1" ino=14553 res=0 ctx_free_ctx drivers/misc/vmw_vmci/vmci_context.c:452 [inline] kref_put include/linux/kref.h:70 [inline] vmci_ctx_put+0x55a/0xd60 drivers/misc/vmw_vmci/vmci_context.c:505 vmci_ctx_enqueue_datagram+0x3f7/0x500 drivers/misc/vmw_vmci/vmci_context.c:368 dg_dispatch_as_host drivers/misc/vmw_vmci/vmci_datagram.c:283 [inline] vmci_datagram_dispatch+0x39b/0xb40 drivers/misc/vmw_vmci/vmci_datagram.c:347 qp_notify_peer+0x182/0x260 drivers/misc/vmw_vmci/vmci_queue_pair.c:1488 vmci_qp_broker_detach+0xa09/0x11b0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2192 ctx_free_ctx drivers/misc/vmw_vmci/vmci_context.c:452 [inline] kref_put include/linux/kref.h:70 [inline] vmci_ctx_put+0x55a/0xd60 drivers/misc/vmw_vmci/vmci_context.c:505 vmci_host_close+0x116/0x1a0 drivers/misc/vmw_vmci/vmci_host.c:147 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4665e9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb60f320188 EFLAGS: 00000246 ORIG_RAX: 0000000000000124 RAX: 0000000000000005 RBX: 000000000056bf80 RCX: 00000000004665e9 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffd0199103f R14: 00007fb60f320300 R15: 0000000000022000 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: ff c3 inc %ebx 2: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) 9: 00 00 00 c: 0f 1f 40 00 nopl 0x0(%rax) 10: 48 89 f8 mov %rdi,%rax 13: 48 89 f7 mov %rsi,%rdi 16: 48 89 d6 mov %rdx,%rsi 19: 48 89 ca mov %rcx,%rdx 1c: 4d 89 c2 mov %r8,%r10 1f: 4d 89 c8 mov %r9,%r8 22: 4c 8b 4c 24 08 mov 0x8(%rsp),%r9 27: 0f 05 syscall 29: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax <-- trapping instruction 2f: 73 01 jae 0x32 31: c3 retq 32: 48 c7 c1 bc ff ff ff mov $0xffffffffffffffbc,%rcx 39: f7 d8 neg %eax 3b: 64 89 01 mov %eax,%fs:(%rcx) 3e: 48 rex.W