Hello, syzbot found the following crash on: HEAD commit: 9d1bc24b bonding: validate ip header before check IPPROTO_.. git tree: net console output: https://syzkaller.appspot.com/x/log.txt?x=1464c78ba00000 kernel config: https://syzkaller.appspot.com/x/.config?x=e7c31a94f66cc0aa dashboard link: https://syzkaller.appspot.com/bug?extid=bf64ec93de836d7f4c2c compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1397378ba00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12f51315a00000 The bug was bisected to: commit 455302d1c9ae9318660aaeb9748a01ff414c9741 Author: Ilya Maximets <i.maximets@xxxxxxxxxxx> Date: Fri Jun 28 08:04:07 2019 +0000 xdp: fix hang while unregistering device bound to xdp socket bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1092d9aba00000 final crash: https://syzkaller.appspot.com/x/report.txt?x=1292d9aba00000 console output: https://syzkaller.appspot.com/x/log.txt?x=1492d9aba00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+bf64ec93de836d7f4c2c@xxxxxxxxxxxxxxxxxxxxxxxxxFixes: 455302d1c9ae ("xdp: fix hang while unregistering device bound to xdp socket")
====================================================== WARNING: possible circular locking dependency detected 5.2.0-rc6+ #75 Not tainted ------------------------------------------------------ syz-executor831/8960 is trying to acquire lock:00000000f6cc1fdf (&xs->mutex){+.+.}, at: xsk_notifier+0x149/0x290 net/xdp/xsk.c:730
but task is already holding lock:00000000f06c3f54 (&net->xdp.lock){+.+.}, at: xsk_notifier+0xa7/0x290 net/xdp/xsk.c:726
which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&net->xdp.lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:926 [inline] __mutex_lock+0xf7/0x1310 kernel/locking/mutex.c:1073 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088 xsk_notifier+0xa7/0x290 net/xdp/xsk.c:726 notifier_call_chain+0xc2/0x230 kernel/notifier.c:95 __raw_notifier_call_chain kernel/notifier.c:396 [inline] raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:403 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1749 call_netdevice_notifiers_extack net/core/dev.c:1761 [inline] call_netdevice_notifiers net/core/dev.c:1775 [inline] rollback_registered_many+0x9b9/0xfc0 net/core/dev.c:8206 rollback_registered+0x109/0x1d0 net/core/dev.c:8248 unregister_netdevice_queue net/core/dev.c:9295 [inline] unregister_netdevice_queue+0x1ee/0x2c0 net/core/dev.c:9288 br_dev_delete+0x145/0x1a0 net/bridge/br_if.c:383 br_del_bridge+0xd7/0x120 net/bridge/br_if.c:483 br_ioctl_deviceless_stub+0x2a4/0x7b0 net/bridge/br_ioctl.c:376 sock_ioctl+0x44b/0x780 net/socket.c:1141 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (rtnl_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:926 [inline] __mutex_lock+0xf7/0x1310 kernel/locking/mutex.c:1073 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 xdp_umem_assign_dev+0xbe/0x8b0 net/xdp/xdp_umem.c:96 xsk_bind+0x4d7/0xe70 net/xdp/xsk.c:488 __sys_bind+0x239/0x290 net/socket.c:1653 __do_sys_bind net/socket.c:1664 [inline] __se_sys_bind net/socket.c:1662 [inline] __x64_sys_bind+0x73/0xb0 net/socket.c:1662 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&xs->mutex){+.+.}: lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4303 __mutex_lock_common kernel/locking/mutex.c:926 [inline] __mutex_lock+0xf7/0x1310 kernel/locking/mutex.c:1073 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088 xsk_notifier+0x149/0x290 net/xdp/xsk.c:730 notifier_call_chain+0xc2/0x230 kernel/notifier.c:95 __raw_notifier_call_chain kernel/notifier.c:396 [inline] raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:403 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1749 call_netdevice_notifiers_extack net/core/dev.c:1761 [inline] call_netdevice_notifiers net/core/dev.c:1775 [inline] rollback_registered_many+0x9b9/0xfc0 net/core/dev.c:8206 rollback_registered+0x109/0x1d0 net/core/dev.c:8248 unregister_netdevice_queue net/core/dev.c:9295 [inline] unregister_netdevice_queue+0x1ee/0x2c0 net/core/dev.c:9288 br_dev_delete+0x145/0x1a0 net/bridge/br_if.c:383 br_del_bridge+0xd7/0x120 net/bridge/br_if.c:483 br_ioctl_deviceless_stub+0x2a4/0x7b0 net/bridge/br_ioctl.c:376 sock_ioctl+0x44b/0x780 net/socket.c:1141 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: &xs->mutex --> rtnl_mutex --> &net->xdp.lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&net->xdp.lock); lock(rtnl_mutex); lock(&net->xdp.lock); lock(&xs->mutex); *** DEADLOCK *** 3 locks held by syz-executor831/8960:#0: 00000000060d4522 (br_ioctl_mutex){+.+.}, at: sock_ioctl+0x427/0x780 net/socket.c:1139 #1: 000000006ae5b4ee (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 #2: 00000000f06c3f54 (&net->xdp.lock){+.+.}, at: xsk_notifier+0xa7/0x290 net/xdp/xsk.c:726
stack backtrace: CPU: 1 PID: 8960 Comm: syz-executor831 Not tainted 5.2.0-rc6+ #75Hardware 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+0x172/0x1f0 lib/dump_stack.c:113 print_circular_bug.cold+0x1cc/0x28f kernel/locking/lockdep.c:1565 check_prev_add kernel/locking/lockdep.c:2310 [inline] check_prevs_add kernel/locking/lockdep.c:2418 [inline] validate_chain kernel/locking/lockdep.c:2800 [inline] __lock_acquire+0x3755/0x5490 kernel/locking/lockdep.c:3793 lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4303 __mutex_lock_common kernel/locking/mutex.c:926 [inline] __mutex_lock+0xf7/0x1310 kernel/locking/mutex.c:1073 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088 xsk_notifier+0x149/0x290 net/xdp/xsk.c:730 notifier_call_chain+0xc2/0x230 kernel/notifier.c:95 __raw_notifier_call_chain kernel/notifier.c:396 [inline] raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:403 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1749 call_netdevice_notifiers_extack net/core/dev.c:1761 [inline] call_netdevice_notifiers net/core/dev.c:1775 [inline] rollback_registered_many+0x9b9/0xfc0 net/core/dev.c:8206 rollback_registered+0x109/0x1d0 net/core/dev.c:8248 unregister_netdevice_queue net/core/dev.c:9295 [inline] unregister_netdevice_queue+0x1ee/0x2c0 net/core/dev.c:9288 br_dev_delete+0x145/0x1a0 net/bridge/br_if.c:383 br_del_bridge+0xd7/0x120 net/bridge/br_if.c:483 br_ioctl_deviceless_stub+0x2a4/0x7b0 net/bridge/br_ioctl.c:376 sock_ioctl+0x44b/0x780 net/socket.c:1141 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x447929Code: e8 cc e7 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 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 0f 83 3b 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f24c6077d98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000006dcc58 RCX: 0000000000447929 RDX: 0000000020000180 RSI: 00000000000089a1 RDI: 0000000000000003 RBP: 00000000006dcc50 R08: 00007f24c6078700 R09: 0000000000000000 R10: 00007f24c6078700 R11: 0000000000000246 R12: 00000000006dcc5c R13: 0000003066736362 R14: 0000000000000000 R15: 0000003066736362 kobject: 'batman_adv' (00000000e09eb5f6): kobject_uevent_envkobject: 'batman_adv' (00000000e09eb5f6): kobject_uevent_env: filter function caused the event to drop! kobject: 'batman_adv' (00000000e09eb5f6): kobject_cleanup, parent 00000000e11c2695
kobject: 'batman_adv' (00000000e09eb5f6): calling ktype release kobject: (00000000e09eb5f6): dynamic_kobj_release kobject: 'batman_adv': free name kobject: 'rx-0' (00000000fc3ea8b5): kobject_cleanup, parent 000000000f96f49f kobject: 'rx-0' (00000000fc3ea8b5): auto cleanup 'remove' event kobject: 'rx-0' (00000000fc3ea8b5): kobject_uevent_envkobject: 'rx-0' (00000000fc3ea8b5): fill_kobj_path: path = '/devices/virtual/net/bcsf0/queues/rx-0'
kobject: 'rx-0' (00000000fc3ea8b5): auto cleanup kobject_del kobject: 'rx-0' (00000000fc3ea8b5): calling ktype release kobject: 'rx-0': free name kobject: 'tx-0' (0000000089e0fc81): kobject_cleanup, parent 000000000f96f49f kobject: 'tx-0' (0000000089e0fc81): auto cleanup 'remove' event kobject: 'tx-0' (0000000089e0fc81): kobject_uevent_envkobject: 'tx-0' (0000000089e0fc81): fill_kobj_path: path = '/devices/virtual/net/bcsf0/queues/tx-0'
kobject: 'tx-0' (0000000089e0fc81): auto cleanup kobject_del kobject: 'tx-0' (0000000089e0fc81): calling ktype release kobject: 'tx-0': free namekobject: 'queues' (000000000f96f49f): kobject_cleanup, parent 00000000e11c2695
kobject: 'queues' (000000000f96f49f): calling ktype release kobject: 'queues' (000000000f96f49f): kset_release kobject: 'queues': free name kobject: 'bcsf0' (00000000e3247f71): kobject_uevent_envkobject: 'bcsf0' (00000000e3247f71): fill_kobj_path: path = '/devices/virtual/net/bcsf0' kobject: 'bcsf0' (00000000e3247f71): kobject_cleanup, parent 00000000e11c2695
kobject: 'bcsf0' (00000000e3247f71): calling ktype release kobject: 'bcsf0': free name --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches
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