Re: [syzbot] [net?] BUG: sleeping function called from invalid context in dev_set_promiscuity

[Stanislav Fomichev <stfomichev@gmail.com>]

On 05/12, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    82f2b0b97b36 Linux 6.15-rc6
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=173c62f4580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=1e4dff0626333635
> dashboard link: https://syzkaller.appspot.com/bug?extid=53485086a41dbb43270a
> compiler:       Debian clang version 20.1.2 (++20250402124445+58df0ef89dd6-1~exp1~20250402004600.97), Debian LLD 20.1.2
> 
> Unfortunately, I don't have any reproducer for this issue yet.
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/900b6a747850/disk-82f2b0b9.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/1d41ddb74da5/vmlinux-82f2b0b9.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/eb555785f64f/bzImage-82f2b0b9.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+53485086a41dbb43270a@syzkaller.appspotmail.com
> 
> team0 (unregistering): left promiscuous mode
> team_slave_0: left promiscuous mode
> team_slave_1: left promiscuous mode
> bond0: left promiscuous mode
> bond_slave_0: left promiscuous mode
> bond_slave_1: left promiscuous mode
> BUG: sleeping function called from invalid context at kernel/locking/mutex.c:578
> in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 14644, name: syz.2.10383
> preempt_count: 0, expected: 0
> RCU nest depth: 1, expected: 0
> 2 locks held by syz.2.10383/14644:
>  #0: ffffffff8f2f6d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
>  #0: ffffffff8f2f6d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
>  #0: ffffffff8f2f6d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x331/0x710 net/core/rtnetlink.c:3556
>  #1: ffffffff8df3d860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
>  #1: ffffffff8df3d860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
>  #1: ffffffff8df3d860 (rcu_read_lock){....}-{1:3}, at: team_change_rx_flags+0x29/0x330 drivers/net/team/team_core.c:1781
> CPU: 1 UID: 0 PID: 14644 Comm: syz.2.10383 Not tainted 6.15.0-rc6-syzkaller #0 PREEMPT(full) 
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
> Call Trace:
>  <TASK>
>  dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
>  __might_resched+0x495/0x610 kernel/sched/core.c:8818
>  __mutex_lock_common kernel/locking/mutex.c:578 [inline]
>  __mutex_lock+0x106/0xe80 kernel/locking/mutex.c:746
>  netdev_lock include/linux/netdevice.h:2751 [inline]
>  netdev_lock_ops include/net/netdev_lock.h:42 [inline]
>  dev_set_promiscuity+0x10e/0x260 net/core/dev_api.c:285
>  bond_set_promiscuity drivers/net/bonding/bond_main.c:922 [inline]
>  bond_change_rx_flags+0x219/0x690 drivers/net/bonding/bond_main.c:4732
>  dev_change_rx_flags net/core/dev.c:9145 [inline]
>  __dev_set_promiscuity+0x3f5/0x590 net/core/dev.c:9189
>  netif_set_promiscuity+0x50/0xe0 net/core/dev.c:9201
>  dev_set_promiscuity+0x126/0x260 net/core/dev_api.c:286
>  team_change_rx_flags+0x1b3/0x330 drivers/net/team/team_core.c:1785
>  dev_change_rx_flags net/core/dev.c:9145 [inline]
>  __dev_set_promiscuity+0x3f5/0x590 net/core/dev.c:9189
>  netif_set_promiscuity+0x50/0xe0 net/core/dev.c:9201
>  dev_set_promiscuity+0x126/0x260 net/core/dev_api.c:286
>  hsr_del_port+0x25e/0x2d0 net/hsr/hsr_slave.c:233
>  hsr_netdev_notify+0x827/0xb60 net/hsr/hsr_main.c:104
>  notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85
>  call_netdevice_notifiers_extack net/core/dev.c:2214 [inline]
>  call_netdevice_notifiers net/core/dev.c:2228 [inline]
>  unregister_netdevice_many_notify+0x15d8/0x2330 net/core/dev.c:11970
>  rtnl_delete_link net/core/rtnetlink.c:3522 [inline]
>  rtnl_dellink+0x488/0x710 net/core/rtnetlink.c:3564
>  rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6955
>  netlink_rcv_skb+0x219/0x490 net/netlink/af_netlink.c:2534
>  netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
>  netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339
>  netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
>  sock_sendmsg_nosec net/socket.c:712 [inline]
>  __sock_sendmsg+0x219/0x270 net/socket.c:727
>  ____sys_sendmsg+0x505/0x830 net/socket.c:2566
>  ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620
>  __sys_sendmsg net/socket.c:2652 [inline]
>  __do_sys_sendmsg net/socket.c:2657 [inline]
>  __se_sys_sendmsg net/socket.c:2655 [inline]
>  __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2655
>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>  do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7f8a8538e969
> 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 a8 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007f8a8298f038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
> RAX: ffffffffffffffda RBX: 00007f8a855b6320 RCX: 00007f8a8538e969
> RDX: 0000000000000000 RSI: 0000200000000200 RDI: 0000000000000008
> RBP: 00007f8a85410ab1 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 0000000000000001 R14: 00007f8a855b6320 R15: 00007f8a856dfa28
>  </TASK>
> 
> =============================
> [ BUG: Invalid wait context ]
> 6.15.0-rc6-syzkaller #0 Tainted: G        W          
> -----------------------------
> syz.2.10383/14644 is trying to lock:
> ffff88805b68cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline]
> ffff88805b68cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline]
> ffff88805b68cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: dev_set_promiscuity+0x10e/0x260 net/core/dev_api.c:285
> other info that might help us debug this:
> context-{5:5}
> 2 locks held by syz.2.10383/14644:
>  #0: ffffffff8f2f6d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
>  #0: ffffffff8f2f6d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
>  #0: ffffffff8f2f6d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x331/0x710 net/core/rtnetlink.c:3556
>  #1: ffffffff8df3d860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
>  #1: ffffffff8df3d860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
>  #1: ffffffff8df3d860 (rcu_read_lock){....}-{1:3}, at: team_change_rx_flags+0x29/0x330 drivers/net/team/team_core.c:1781
> stack backtrace:
> CPU: 1 UID: 0 PID: 14644 Comm: syz.2.10383 Tainted: G        W           6.15.0-rc6-syzkaller #0 PREEMPT(full) 
> Tainted: [W]=WARN
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
> Call Trace:
>  <TASK>
>  dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
>  print_lock_invalid_wait_context kernel/locking/lockdep.c:4831 [inline]
>  check_wait_context kernel/locking/lockdep.c:4903 [inline]
>  __lock_acquire+0xbcf/0xd20 kernel/locking/lockdep.c:5185
>  lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866
>  __mutex_lock_common kernel/locking/mutex.c:601 [inline]
>  __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746
>  netdev_lock include/linux/netdevice.h:2751 [inline]
>  netdev_lock_ops include/net/netdev_lock.h:42 [inline]
>  dev_set_promiscuity+0x10e/0x260 net/core/dev_api.c:285
>  bond_set_promiscuity drivers/net/bonding/bond_main.c:922 [inline]
>  bond_change_rx_flags+0x219/0x690 drivers/net/bonding/bond_main.c:4732
>  dev_change_rx_flags net/core/dev.c:9145 [inline]
>  __dev_set_promiscuity+0x3f5/0x590 net/core/dev.c:9189
>  netif_set_promiscuity+0x50/0xe0 net/core/dev.c:9201
>  dev_set_promiscuity+0x126/0x260 net/core/dev_api.c:286
>  team_change_rx_flags+0x1b3/0x330 drivers/net/team/team_core.c:1785
>  dev_change_rx_flags net/core/dev.c:9145 [inline]
>  __dev_set_promiscuity+0x3f5/0x590 net/core/dev.c:9189
>  netif_set_promiscuity+0x50/0xe0 net/core/dev.c:9201
>  dev_set_promiscuity+0x126/0x260 net/core/dev_api.c:286
>  hsr_del_port+0x25e/0x2d0 net/hsr/hsr_slave.c:233
>  hsr_netdev_notify+0x827/0xb60 net/hsr/hsr_main.c:104
>  notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85
>  call_netdevice_notifiers_extack net/core/dev.c:2214 [inline]
>  call_netdevice_notifiers net/core/dev.c:2228 [inline]
>  unregister_netdevice_many_notify+0x15d8/0x2330 net/core/dev.c:11970
>  rtnl_delete_link net/core/rtnetlink.c:3522 [inline]
>  rtnl_dellink+0x488/0x710 net/core/rtnetlink.c:3564
>  rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6955
>  netlink_rcv_skb+0x219/0x490 net/netlink/af_netlink.c:2534
>  netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
>  netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339
>  netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
>  sock_sendmsg_nosec net/socket.c:712 [inline]
>  __sock_sendmsg+0x219/0x270 net/socket.c:727
>  ____sys_sendmsg+0x505/0x830 net/socket.c:2566
>  ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620
>  __sys_sendmsg net/socket.c:2652 [inline]
>  __do_sys_sendmsg net/socket.c:2657 [inline]
>  __se_sys_sendmsg net/socket.c:2655 [inline]
>  __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2655
>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>  do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7f8a8538e969
> 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 a8 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007f8a8298f038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
> RAX: ffffffffffffffda RBX: 00007f8a855b6320 RCX: 00007f8a8538e969
> RDX: 0000000000000000 RSI: 0000200000000200 RDI: 0000000000000008
> RBP: 00007f8a85410ab1 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 0000000000000001 R14: 00007f8a855b6320 R15: 00007f8a856dfa28
>  </TASK>
> netdevsim netdevsim2 netdevsim0: left promiscuous mode
> team0 (unregistering): Port device team_slave_0 removed
> team0 (unregistering): Port device team_slave_1 removed
> team0 (unregistering): Port device bond0 removed
> 
> 
> ---
> This report 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@googlegroups.com.
> 
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> 
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
> 
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
> 
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
> 
> If you want to undo deduplication, reply with:
> #syz undup

Replacing rcu_read_lock with team->lock in team_change_rx_flags should
help in theory.. Gonna try.