====================================================== WARNING: possible circular locking dependency detected 5.2.0+ #35 Not tainted ------------------------------------------------------ syz-executor.5/11259 is trying to acquire lock: 00000000e620338b (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 /net/core/rtnetlink.c:72 but task is already holding lock: 00000000dcb4447d (&xs->mutex){+.+.}, at: xsk_bind+0x16e/0xca0 /net/xdp/xsk.c:436 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&xs->mutex){+.+.}: __mutex_lock_common+0x17c/0x2850 /kernel/locking/mutex.c:926 __mutex_lock /kernel/locking/mutex.c:1073 [inline] mutex_lock_nested+0x1b/0x30 /kernel/locking/mutex.c:1088 xsk_notifier+0xe7/0x3b0 /net/xdp/xsk.c:764 notifier_call_chain /kernel/notifier.c:95 [inline] __raw_notifier_call_chain /kernel/notifier.c:396 [inline] raw_notifier_call_chain+0xec/0x190 /kernel/notifier.c:403 call_netdevice_notifiers_info /net/core/dev.c:1749 [inline] call_netdevice_notifiers_extack /net/core/dev.c:1761 [inline] call_netdevice_notifiers /net/core/dev.c:1775 [inline] rollback_registered_many+0xd46/0x1410 /net/core/dev.c:8196 rollback_registered /net/core/dev.c:8238 [inline] unregister_netdevice_queue+0x333/0x500 /net/core/dev.c:9285 unregister_netdevice /./include/linux/netdevice.h:2631 [inline] __tun_detach+0x1101/0x1a90 /drivers/net/tun.c:723 tun_detach /drivers/net/tun.c:740 [inline] tun_chr_close+0xf1/0x130 /drivers/net/tun.c:3439 __fput+0x2e4/0x740 /fs/file_table.c:280 ____fput+0x15/0x20 /fs/file_table.c:313 task_work_run+0x17e/0x1b0 /kernel/task_work.c:113 tracehook_notify_resume /./include/linux/tracehook.h:188 [inline] exit_to_usermode_loop /arch/x86/entry/common.c:163 [inline] prepare_exit_to_usermode+0x459/0x580 /arch/x86/entry/common.c:194 syscall_return_slowpath+0x113/0x4a0 /arch/x86/entry/common.c:274 do_syscall_64+0x126/0x140 /arch/x86/entry/common.c:299 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&net->xdp.lock){+.+.}: __mutex_lock_common+0x17c/0x2850 /kernel/locking/mutex.c:926 __mutex_lock /kernel/locking/mutex.c:1073 [inline] mutex_lock_nested+0x1b/0x30 /kernel/locking/mutex.c:1088 xsk_notifier+0x8c/0x3b0 /net/xdp/xsk.c:760 notifier_call_chain /kernel/notifier.c:95 [inline] __raw_notifier_call_chain /kernel/notifier.c:396 [inline] raw_notifier_call_chain+0xec/0x190 /kernel/notifier.c:403 call_netdevice_notifiers_info /net/core/dev.c:1749 [inline] call_netdevice_notifiers_extack /net/core/dev.c:1761 [inline] call_netdevice_notifiers /net/core/dev.c:1775 [inline] rollback_registered_many+0xd46/0x1410 /net/core/dev.c:8196 rollback_registered /net/core/dev.c:8238 [inline] unregister_netdevice_queue+0x333/0x500 /net/core/dev.c:9285 unregister_netdevice /./include/linux/netdevice.h:2631 [inline] __tun_detach+0x1101/0x1a90 /drivers/net/tun.c:723 tun_detach /drivers/net/tun.c:740 [inline] tun_chr_close+0xf1/0x130 /drivers/net/tun.c:3439 __fput+0x2e4/0x740 /fs/file_table.c:280 ____fput+0x15/0x20 /fs/file_table.c:313 task_work_run+0x17e/0x1b0 /kernel/task_work.c:113 exit_task_work /./include/linux/task_work.h:22 [inline] do_exit+0x64c/0x2310 /kernel/exit.c:877 do_group_exit+0x15c/0x2b0 /kernel/exit.c:981 __do_sys_exit_group+0x17/0x20 /kernel/exit.c:992 __se_sys_exit_group+0x14/0x20 /kernel/exit.c:990 __x64_sys_exit_group+0x3b/0x40 /kernel/exit.c:990 do_syscall_64+0xfe/0x140 /arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (rtnl_mutex){+.+.}: validate_chain /kernel/locking/lockdep.c:2897 [inline] __lock_acquire+0x2531/0x4750 /kernel/locking/lockdep.c:3880 lock_acquire+0x158/0x250 /kernel/locking/lockdep.c:4413 __mutex_lock_common+0x17c/0x2850 /kernel/locking/mutex.c:926 __mutex_lock /kernel/locking/mutex.c:1073 [inline] mutex_lock_nested+0x1b/0x30 /kernel/locking/mutex.c:1088 rtnl_lock+0x17/0x20 /net/core/rtnetlink.c:72 xdp_umem_assign_dev+0xce/0x850 /net/xdp/xdp_umem.c:96 xsk_bind+0x4ab/0xca0 /net/xdp/xsk.c:502 __sys_bind+0x305/0x400 /net/socket.c:1643 __do_sys_bind /net/socket.c:1654 [inline] __se_sys_bind /net/socket.c:1652 [inline] __x64_sys_bind+0x7a/0x90 /net/socket.c:1652 do_syscall_64+0xfe/0x140 /arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: rtnl_mutex --> &net->xdp.lock --> &xs->mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&xs->mutex); lock(&net->xdp.lock); lock(&xs->mutex); lock(rtnl_mutex); *** DEADLOCK *** 1 lock held by syz-executor.5/11259: #0: 00000000dcb4447d (&xs->mutex){+.+.}, at: xsk_bind+0x16e/0xca0 /net/xdp/xsk.c:436 stack backtrace: CPU: 1 PID: 11259 Comm: syz-executor.5 Not tainted 5.2.0+ #35 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+0x1d8/0x2f8 /lib/dump_stack.c:113 print_circular_bug+0xd64/0xf50 /kernel/locking/lockdep.c:1616 check_noncircular+0x30d/0x560 /kernel/locking/lockdep.c:1741 check_prev_add /kernel/locking/lockdep.c:2405 [inline] check_prevs_add+0x560/0x5950 /kernel/locking/lockdep.c:2507 validate_chain /kernel/locking/lockdep.c:2897 [inline] __lock_acquire+0x2531/0x4750 /kernel/locking/lockdep.c:3880 lock_acquire+0x158/0x250 /kernel/locking/lockdep.c:4413 __mutex_lock_common+0x17c/0x2850 /kernel/locking/mutex.c:926 __mutex_lock /kernel/locking/mutex.c:1073 [inline] mutex_lock_nested+0x1b/0x30 /kernel/locking/mutex.c:1088 rtnl_lock+0x17/0x20 /net/core/rtnetlink.c:72 xdp_umem_assign_dev+0xce/0x850 /net/xdp/xdp_umem.c:96 xsk_bind+0x4ab/0xca0 /net/xdp/xsk.c:502 __sys_bind+0x305/0x400 /net/socket.c:1643 __do_sys_bind /net/socket.c:1654 [inline] __se_sys_bind /net/socket.c:1652 [inline] __x64_sys_bind+0x7a/0x90 /net/socket.c:1652 do_syscall_64+0xfe/0x140 /arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459819 Code: fd b7 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa256854c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000031 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459819 RDX: 0000000000000010 RSI: 0000000020000300 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa2568556d4 R13: 00000000004bfa6d R14: 00000000004d1450 R15: 00000000ffffffff