[syzbot] [wireless?] possible deadlock in ieee80211_change_mac (3)

[syzbot <syzbot+30de9d963fdd95d745f8@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    89d75c4c67ac Merge branch 'mlx5-next' of git://git.kernel...
git tree:       net-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=15941698580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=ca99d9d1f4a8ecfa
dashboard link: https://syzkaller.appspot.com/bug?extid=30de9d963fdd95d745f8
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12ebddb0580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=115beff8580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/42d0e44c785b/disk-89d75c4c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a15a82bda0f1/vmlinux-89d75c4c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/51341d6e7b24/bzImage-89d75c4c.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+30de9d963fdd95d745f8@syzkaller.appspotmail.com

netlink: 'syz-executor330': attribute type 10 has an invalid length.
======================================================
WARNING: possible circular locking dependency detected
6.14.0-rc5-syzkaller-01215-g89d75c4c67ac #0 Not tainted
------------------------------------------------------
syz-executor330/5838 is trying to acquire lock:
ffff888021b08768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6063 [inline]
ffff888021b08768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_change_mac+0xc6/0x1160 net/mac80211/iface.c:307

but task is already holding lock:
ffff88807a458d28 (&dev->lock){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2731 [inline]
ffff88807a458d28 (&dev->lock){+.+.}-{4:4}, at: dev_set_mac_address+0x2a/0x50 net/core/dev_api.c:302

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&dev->lock){+.+.}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730
       netdev_lock include/linux/netdevice.h:2731 [inline]
       register_netdevice+0x12d8/0x1b70 net/core/dev.c:10991
       cfg80211_register_netdevice+0x149/0x2f0 net/wireless/core.c:1482
       ieee80211_if_add+0x119d/0x1780 net/mac80211/iface.c:2225
       ieee80211_register_hw+0x3708/0x42e0 net/mac80211/main.c:1604
       mac80211_hwsim_new_radio+0x2a89/0x49f0 drivers/net/wireless/virtual/mac80211_hwsim.c:5559
       init_mac80211_hwsim+0x87a/0xb00 drivers/net/wireless/virtual/mac80211_hwsim.c:6911
       do_one_initcall+0x248/0x930 init/main.c:1257
       do_initcall_level+0x157/0x210 init/main.c:1319
       do_initcalls+0x71/0xd0 init/main.c:1335
       kernel_init_freeable+0x435/0x5d0 init/main.c:1568
       kernel_init+0x1d/0x2b0 init/main.c:1457
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #0 (&rdev->wiphy.mtx){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3163 [inline]
       check_prevs_add kernel/locking/lockdep.c:3282 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
       __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730
       class_wiphy_constructor include/net/cfg80211.h:6063 [inline]
       ieee80211_change_mac+0xc6/0x1160 net/mac80211/iface.c:307
       netif_set_mac_address+0x327/0x510 net/core/dev.c:9587
       dev_set_mac_address+0x38/0x50 net/core/dev_api.c:303
       bond_enslave+0xff3/0x3910 drivers/net/bonding/bond_main.c:2123
       do_set_master+0x579/0x730 net/core/rtnetlink.c:2943
       do_setlink+0xfee/0x40f0 net/core/rtnetlink.c:3149
       rtnl_changelink net/core/rtnetlink.c:3759 [inline]
       __rtnl_newlink net/core/rtnetlink.c:3918 [inline]
       rtnl_newlink+0x15a6/0x1d90 net/core/rtnetlink.c:4055
       rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6945
       netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2534
       netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
       netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1339
       netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1883
       sock_sendmsg_nosec net/socket.c:709 [inline]
       __sock_sendmsg+0x221/0x270 net/socket.c:724
       ____sys_sendmsg+0x53a/0x860 net/socket.c:2564
       ___sys_sendmsg net/socket.c:2618 [inline]
       __sys_sendmsg+0x269/0x350 net/socket.c:2650
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&dev->lock);
                               lock(&rdev->wiphy.mtx);
                               lock(&dev->lock);
  lock(&rdev->wiphy.mtx);

 *** DEADLOCK ***

2 locks held by syz-executor330/5838:
 #0: ffffffff8fed6908 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8fed6908 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #0: ffffffff8fed6908 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc4c/0x1d90 net/core/rtnetlink.c:4054
 #1: ffff88807a458d28 (&dev->lock){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2731 [inline]
 #1: ffff88807a458d28 (&dev->lock){+.+.}-{4:4}, at: dev_set_mac_address+0x2a/0x50 net/core/dev_api.c:302

stack backtrace:
CPU: 1 UID: 0 PID: 5838 Comm: syz-executor330 Not tainted 6.14.0-rc5-syzkaller-01215-g89d75c4c67ac #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2076
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2208
 check_prev_add kernel/locking/lockdep.c:3163 [inline]
 check_prevs_add kernel/locking/lockdep.c:3282 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730
 class_wiphy_constructor include/net/cfg80211.h:6063 [inline]
 ieee80211_change_mac+0xc6/0x1160 net/mac80211/iface.c:307
 netif_set_mac_address+0x327/0x510 net/core/dev.c:9587
 dev_set_mac_address+0x38/0x50 net/core/dev_api.c:303
 bond_enslave+0xff3/0x3910 drivers/net/bonding/bond_main.c:2123
 do_set_master+0x579/0x730 net/core/rtnetlink.c:2943
 do_setlink+0xfee/0x40f0 net/core/rtnetlink.c:3149
 rtnl_changelink net/core/rtnetlink.c:3759 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3918 [inline]
 rtnl_newlink+0x15a6/0x1d90 net/core/rtnetlink.c:4055
 rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6945
 netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2534
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:709 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:724
 ____sys_sendmsg+0x53a/0x860 net/socket.c:2564
 ___sys_sendmsg net/socket.c:2618 [inline]
 __sys_sendmsg+0x269/0x350 net/socket.c:2650
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f76fec11329
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 1a 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff4bb2f358 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f76fec5e513 RCX: 00007f76fec11329
RDX: 0000000000000000 RSI: 0000400000000600 RDI: 0000000000000003
RBP: 00007f76fec5e4e3 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f76fec5e44b
R13: 0000000000000048 R14: 0000000000050012 R15: 0000000000000003
 </TASK>
bond0: (slave wlan1): Enslaving as an active interface with an up link


---
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