[syzbot] [net?] possible deadlock in team_port_change_check (2)

From: syzbot
Date: Thu Feb 29 2024 - 11:21:58 EST


Hello,

syzbot found the following issue on:

HEAD commit: 2a770cdc4382 tun: Fix xdp_rxq_info's queue_index when deta..
git tree: net
console output: https://syzkaller.appspot.com/x/log.txt?x=11bfb032180000
kernel config: https://syzkaller.appspot.com/x/.config?x=eff9f3183d0a20dd
dashboard link: https://syzkaller.appspot.com/bug?extid=3c47b5843403a45aef57
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/54ceb0944449/disk-2a770cdc.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/69b79e7b7a86/vmlinux-2a770cdc.xz
kernel image: https://storage.googleapis.com/syzbot-assets/dedbc599c2f7/bzImage-2a770cdc.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3c47b5843403a45aef57@xxxxxxxxxxxxxxxxxxxxxxxxx

============================================
WARNING: possible recursive locking detected
6.8.0-rc5-syzkaller-00129-g2a770cdc4382 #0 Not tainted
--------------------------------------------
syz-executor.1/20275 is trying to acquire lock:
ffff888045338d00 (team->team_lock_key#2){+.+.}-{3:3}, at: team_port_change_check+0x51/0x1e0 drivers/net/team/team.c:2997

but task is already holding lock:
ffff888045338d00 (team->team_lock_key#2){+.+.}-{3:3}, at: team_add_slave+0xad/0x2750 drivers/net/team/team.c:1974

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(team->team_lock_key#2);
lock(team->team_lock_key#2);

*** DEADLOCK ***

May be due to missing lock nesting notation

2 locks held by syz-executor.1/20275:
#0: ffffffff8f3759c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8f3759c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x82c/0x1040 net/core/rtnetlink.c:6615
#1: ffff888045338d00 (team->team_lock_key#2){+.+.}-{3:3}, at: team_add_slave+0xad/0x2750 drivers/net/team/team.c:1974

stack backtrace:
CPU: 0 PID: 20275 Comm: syz-executor.1 Not tainted 6.8.0-rc5-syzkaller-00129-g2a770cdc4382 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
check_deadlock kernel/locking/lockdep.c:3062 [inline]
validate_chain+0x15c0/0x58e0 kernel/locking/lockdep.c:3856
__lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
team_port_change_check+0x51/0x1e0 drivers/net/team/team.c:2997
team_device_event+0x161/0x5b0 drivers/net/team/team.c:3023
notifier_call_chain+0x18f/0x3b0 kernel/notifier.c:93
call_netdevice_notifiers_extack net/core/dev.c:2004 [inline]
call_netdevice_notifiers net/core/dev.c:2018 [inline]
dev_close_many+0x33c/0x4c0 net/core/dev.c:1559
vlan_device_event+0x18b7/0x1de0 net/8021q/vlan.c:449
notifier_call_chain+0x18f/0x3b0 kernel/notifier.c:93
call_netdevice_notifiers_extack net/core/dev.c:2004 [inline]
call_netdevice_notifiers net/core/dev.c:2018 [inline]
dev_close_many+0x33c/0x4c0 net/core/dev.c:1559
dev_close+0x1c0/0x2c0 net/core/dev.c:1581
team_port_add drivers/net/team/team.c:1312 [inline]
team_add_slave+0x1aef/0x2750 drivers/net/team/team.c:1975
do_set_master net/core/rtnetlink.c:2707 [inline]
do_setlink+0xe58/0x41c0 net/core/rtnetlink.c:2913
rtnl_setlink+0x40d/0x5a0 net/core/rtnetlink.c:3209
rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6618
netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543
netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367
netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0x221/0x270 net/socket.c:745
sock_write_iter+0x2dd/0x400 net/socket.c:1160
do_iter_readv_writev+0x46c/0x640
vfs_writev+0x395/0xbb0 fs/read_write.c:971
do_writev+0x1b1/0x350 fs/read_write.c:1018
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7ff40be7dda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff40cb2f0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007ff40bfabf80 RCX: 00007ff40be7dda9
RDX: 0000000000000001 RSI: 0000000020000400 RDI: 0000000000000003
RBP: 00007ff40beca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007ff40bfabf80 R15: 00007ffdeb79a408
</TASK>


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