syzbot

======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.2.12426/19584 is trying to acquire lock:
ffff888081c423c8 (kn->active#11){++++}-{0:0}, at: __kernfs_remove+0x3cf/0x660 fs/kernfs/dir.c:1513

but task is already holding lock:
ffff88808f208788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6441 [inline]
ffff88808f208788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_remove_interfaces+0x132/0x6d0 net/mac80211/iface.c:2415

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&rdev->wiphy.mtx){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:614 [inline]
       __mutex_lock+0x19f/0x1300 kernel/locking/mutex.c:776
       class_wiphy_constructor include/net/cfg80211.h:6441 [inline]
       ieee80211_change_mac+0xb5/0x1410 net/mac80211/iface.c:324
       netif_set_mac_address+0x317/0x4e0 net/core/dev.c:9998
       do_setlink+0x9b1/0x4590 net/core/rtnetlink.c:3110
       rtnl_changelink net/core/rtnetlink.c:3776 [inline]
       __rtnl_newlink net/core/rtnetlink.c:3935 [inline]
       rtnl_newlink+0x15a9/0x1be0 net/core/rtnetlink.c:4072
       rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958
       netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
       netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
       netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344
       netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
       sock_sendmsg_nosec net/socket.c:727 [inline]
       __sock_sendmsg net/socket.c:742 [inline]
       ____sys_sendmsg+0xa68/0xad0 net/socket.c:2592
       ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646
       __sys_sendmsg net/socket.c:2678 [inline]
       __do_sys_sendmsg net/socket.c:2683 [inline]
       __se_sys_sendmsg net/socket.c:2681 [inline]
       __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (dev_addr_sem){++++}-{4:4}:
       down_read+0x47/0x2e0 kernel/locking/rwsem.c:1537
       address_show+0x25/0x250 net/core/net-sysfs.c:266
       dev_attr_show+0x58/0xc0 drivers/base/core.c:2421
       sysfs_kf_seq_show+0x310/0x490 fs/sysfs/file.c:65
       seq_read_iter+0x4ef/0xe10 fs/seq_file.c:231
       new_sync_read fs/read_write.c:493 [inline]
       vfs_read+0x582/0xa70 fs/read_write.c:574
       ksys_read+0x150/0x270 fs/read_write.c:717
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (kn->active#11){++++}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
       kernfs_drain+0x284/0x600 fs/kernfs/dir.c:511
       __kernfs_remove+0x3cf/0x660 fs/kernfs/dir.c:1513
       kernfs_remove_by_name_ns+0xaf/0x130 fs/kernfs/dir.c:1722
       kernfs_remove_by_name include/linux/kernfs.h:633 [inline]
       remove_files fs/sysfs/group.c:28 [inline]
       sysfs_remove_group+0xfc/0x2e0 fs/sysfs/group.c:328
       sysfs_remove_groups+0x54/0xb0 fs/sysfs/group.c:352
       device_remove_groups drivers/base/core.c:2843 [inline]
       device_remove_attrs+0x229/0x280 drivers/base/core.c:2979
       device_del+0x51f/0x8f0 drivers/base/core.c:3877
       unregister_netdevice_many_notify+0x1e0e/0x2370 net/core/dev.c:12447
       unregister_netdevice_many net/core/dev.c:12475 [inline]
       unregister_netdevice_queue+0x31f/0x360 net/core/dev.c:12289
       unregister_netdevice include/linux/netdevice.h:3408 [inline]
       _cfg80211_unregister_wdev+0x155/0x570 net/wireless/core.c:1297
       ieee80211_remove_interfaces+0x49c/0x6d0 net/mac80211/iface.c:2440
       ieee80211_unregister_hw+0x5d/0x2c0 net/mac80211/main.c:1690
       mac80211_hwsim_del_radio+0x28a/0x490 drivers/net/wireless/virtual/mac80211_hwsim.c:5916
       remove_user_radios drivers/net/wireless/virtual/mac80211_hwsim.c:6727 [inline]
       mac80211_hwsim_netlink_notify+0xfae/0x1310 drivers/net/wireless/virtual/mac80211_hwsim.c:6741
       notifier_call_chain+0x1be/0x400 kernel/notifier.c:85
       blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380
       netlink_release+0x123b/0x1ad0 net/netlink/af_netlink.c:761
       __sock_release net/socket.c:662 [inline]
       sock_close+0xc3/0x240 net/socket.c:1455
       __fput+0x44f/0xa70 fs/file_table.c:469
       task_work_run+0x1d9/0x270 kernel/task_work.c:233
       resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
       __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
       exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
       __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
       syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
       syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
       do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  kn->active#11 --> dev_addr_sem --> &rdev->wiphy.mtx

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&rdev->wiphy.mtx);
                               lock(dev_addr_sem);
                               lock(&rdev->wiphy.mtx);
  lock(kn->active#11);

 *** DEADLOCK ***

4 locks held by syz.2.12426/19584:
 #0: ffff888056a67508 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
 #0: ffff888056a67508 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline]
 #0: ffff888056a67508 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455
 #1: ffffffff8fc38530 ((netlink_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x54/0x90 kernel/notifier.c:379
 #2: ffffffff8fbcc888 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x55/0x2c0 net/mac80211/main.c:1683
 #3: ffff88808f208788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6441 [inline]
 #3: ffff88808f208788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_remove_interfaces+0x132/0x6d0 net/mac80211/iface.c:2415

stack backtrace:
CPU: 0 UID: 0 PID: 19584 Comm: syz.2.12426 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043
 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
 kernfs_drain+0x284/0x600 fs/kernfs/dir.c:511
 __kernfs_remove+0x3cf/0x660 fs/kernfs/dir.c:1513
 kernfs_remove_by_name_ns+0xaf/0x130 fs/kernfs/dir.c:1722
 kernfs_remove_by_name include/linux/kernfs.h:633 [inline]
 remove_files fs/sysfs/group.c:28 [inline]
 sysfs_remove_group+0xfc/0x2e0 fs/sysfs/group.c:328
 sysfs_remove_groups+0x54/0xb0 fs/sysfs/group.c:352
 device_remove_groups drivers/base/core.c:2843 [inline]
 device_remove_attrs+0x229/0x280 drivers/base/core.c:2979
 device_del+0x51f/0x8f0 drivers/base/core.c:3877
 unregister_netdevice_many_notify+0x1e0e/0x2370 net/core/dev.c:12447
 unregister_netdevice_many net/core/dev.c:12475 [inline]
 unregister_netdevice_queue+0x31f/0x360 net/core/dev.c:12289
 unregister_netdevice include/linux/netdevice.h:3408 [inline]
 _cfg80211_unregister_wdev+0x155/0x570 net/wireless/core.c:1297
 ieee80211_remove_interfaces+0x49c/0x6d0 net/mac80211/iface.c:2440
 ieee80211_unregister_hw+0x5d/0x2c0 net/mac80211/main.c:1690
 mac80211_hwsim_del_radio+0x28a/0x490 drivers/net/wireless/virtual/mac80211_hwsim.c:5916
 remove_user_radios drivers/net/wireless/virtual/mac80211_hwsim.c:6727 [inline]
 mac80211_hwsim_netlink_notify+0xfae/0x1310 drivers/net/wireless/virtual/mac80211_hwsim.c:6741
 notifier_call_chain+0x1be/0x400 kernel/notifier.c:85
 blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380
 netlink_release+0x123b/0x1ad0 net/netlink/af_netlink.c:761
 __sock_release net/socket.c:662 [inline]
 sock_close+0xc3/0x240 net/socket.c:1455
 __fput+0x44f/0xa70 fs/file_table.c:469
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f135a19c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f135afb6028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: 0000000000000018 RBX: 00007f135a415fa0 RCX: 00007f135a19c799
RDX: 0000000000000300 RSI: 0000200000000040 RDI: 0000000000000004
RBP: 00007f135a232bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f135a416038 R14: 00007f135a415fa0 R15: 00007ffe313b2b88
 </TASK>