possible deadlock in ext4_file_write_iter (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=126b18fdb00000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=d0bf53989411f8e4778f
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d0bf53...@syzkaller.appspotmail.com

device bridge1 entered promiscuous mode
overlayfs: missing 'lowerdir'
======================================================
WARNING: possible circular locking dependency detected
4.19.211-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.2/10136 is trying to acquire lock:
000000005b586282 ((wq_completion)"dio/%s"sb->s_id){+.+.}, at: flush_workqueue+0xe8/0x13e0 kernel/workqueue.c:2658
overlayfs: fs on './file0' does not support file handles, falling back to index=off,nfs_export=off.

but task is already holding lock:
000000001af3abea (&sb->s_type->i_mutex_key#10){+.+.}, at: inode_trylock include/linux/fs.h:768 [inline]
000000001af3abea (&sb->s_type->i_mutex_key#10){+.+.}, at: ext4_file_write_iter+0x21f/0xf20 fs/ext4/file.c:238

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&sb->s_type->i_mutex_key#10){+.+.}:
inode_lock include/linux/fs.h:748 [inline]
__generic_file_fsync+0xb0/0x1f0 fs/libfs.c:989
ext4_sync_file+0xa35/0x1420 fs/ext4/fsync.c:118
vfs_fsync_range+0x13a/0x220 fs/sync.c:197
generic_write_sync include/linux/fs.h:2750 [inline]
dio_complete+0x763/0xac0 fs/direct-io.c:329
process_one_work+0x864/0x1570 kernel/workqueue.c:2153
FAT-fs (loop3): Unrecognized mount option "measure" or missing value
worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

-> #1 ((work_completion)(&dio->complete_work)){+.+.}:
netlink: 12 bytes leftover after parsing attributes in process `syz-executor.1'.
worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

-> #0 ((wq_completion)"dio/%s"sb->s_id){+.+.}:
flush_workqueue+0x117/0x13e0 kernel/workqueue.c:2661
drain_workqueue+0x1a5/0x460 kernel/workqueue.c:2826
destroy_workqueue+0x75/0x790 kernel/workqueue.c:4183
sb_init_dio_done_wq+0x72/0x90 fs/direct-io.c:634
do_blockdev_direct_IO fs/direct-io.c:1285 [inline]
__blockdev_direct_IO+0x5f55/0xef40 fs/direct-io.c:1419
ext4_direct_IO_write fs/ext4/inode.c:3777 [inline]
ext4_direct_IO+0xae4/0x1c50 fs/ext4/inode.c:3915
generic_file_direct_write+0x208/0x4a0 mm/filemap.c:3073
__generic_file_write_iter+0x2d0/0x610 mm/filemap.c:3252
ext4_file_write_iter+0x2fe/0xf20 fs/ext4/file.c:272
call_write_iter include/linux/fs.h:1821 [inline]
aio_write+0x37f/0x5c0 fs/aio.c:1574
__io_submit_one fs/aio.c:1858 [inline]
io_submit_one+0xecd/0x20c0 fs/aio.c:1909
__do_sys_io_submit fs/aio.c:1953 [inline]
__se_sys_io_submit+0x11b/0x4a0 fs/aio.c:1924
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

other info that might help us debug this:

Chain exists of:
(wq_completion)"dio/%s"sb->s_id --> (work_completion)(&dio->complete_work) --> &sb->s_type->i_mutex_key#10

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&sb->s_type->i_mutex_key#10);
lock((work_completion)(&dio->complete_work));
lock(&sb->s_type->i_mutex_key#10);
lock((wq_completion)"dio/%s"sb->s_id);

*** DEADLOCK ***

1 lock held by syz-executor.2/10136:
#0: 000000001af3abea (&sb->s_type->i_mutex_key#10){+.+.}, at: inode_trylock include/linux/fs.h:768 [inline]
#0: 000000001af3abea (&sb->s_type->i_mutex_key#10){+.+.}, at: ext4_file_write_iter+0x21f/0xf20 fs/ext4/file.c:238

stack backtrace:
CPU: 1 PID: 10136 Comm: syz-executor.2 Not tainted 4.19.211-syzkaller #0
Hardware 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+0x1fc/0x2ef lib/dump_stack.c:118
print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1222
check_prev_add kernel/locking/lockdep.c:1866 [inline]
check_prevs_add kernel/locking/lockdep.c:1979 [inline]
validate_chain kernel/locking/lockdep.c:2420 [inline]
__lock_acquire+0x30c9/0x3ff0 kernel/locking/lockdep.c:3416
lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908
flush_workqueue+0x117/0x13e0 kernel/workqueue.c:2661
drain_workqueue+0x1a5/0x460 kernel/workqueue.c:2826
destroy_workqueue+0x75/0x790 kernel/workqueue.c:4183
sb_init_dio_done_wq+0x72/0x90 fs/direct-io.c:634
do_blockdev_direct_IO fs/direct-io.c:1285 [inline]
__blockdev_direct_IO+0x5f55/0xef40 fs/direct-io.c:1419
ext4_direct_IO_write fs/ext4/inode.c:3777 [inline]
ext4_direct_IO+0xae4/0x1c50 fs/ext4/inode.c:3915
generic_file_direct_write+0x208/0x4a0 mm/filemap.c:3073
__generic_file_write_iter+0x2d0/0x610 mm/filemap.c:3252
ext4_file_write_iter+0x2fe/0xf20 fs/ext4/file.c:272
call_write_iter include/linux/fs.h:1821 [inline]
aio_write+0x37f/0x5c0 fs/aio.c:1574
__io_submit_one fs/aio.c:1858 [inline]
io_submit_one+0xecd/0x20c0 fs/aio.c:1909
__do_sys_io_submit fs/aio.c:1953 [inline]
__se_sys_io_submit+0x11b/0x4a0 fs/aio.c:1924
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f0ff45c8e99
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0ff2f1d168 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1
RAX: ffffffffffffffda RBX: 00007f0ff46dc030 RCX: 00007f0ff45c8e99
RDX: 0000000020000540 RSI: 0000000000001853 RDI: 00007f0ff46b7000
RBP: 00007f0ff4622ff1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffea065815f R14: 00007f0ff2f1d300 R15: 0000000000022000
FAT-fs (loop0): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1)
overlayfs: missing 'lowerdir'
FAT-fs (loop3): Unrecognized mount option "measure" or missing value
overlayfs: fs on './file0' does not support file handles, falling back to index=off,nfs_export=off.
device bridge2 entered promiscuous mode
FS-Cache: Duplicate cookie detected
FS-Cache: O-cookie c=00000000c8b06539 [p=000000000cf79f39 fl=212 nc=0 na=0]
FS-Cache: O-cookie d= (null) n= (null)
FS-Cache: O-key=[16] '02000000000000000200010073680000'
FS-Cache: N-cookie c=00000000f88b91be [p=000000000cf79f39 fl=2 nc=0 na=1]
FS-Cache: N-cookie d=000000006cda2141 n=00000000c5683f68
FS-Cache: N-key=[16] '02000000000000000200010073680000'
netlink: 12 bytes leftover after parsing attributes in process `syz-executor.2'.
overlayfs: missing 'lowerdir'
FAT-fs (loop2): Unrecognized mount option "measure" or missing value
device bridge1 entered promiscuous mode
overlayfs: missing 'lowerdir'
overlayfs: missing 'lowerdir'
FAT-fs (loop4): Unrecognized mount option "measure" or missing value
FAT-fs (loop0): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1)
FAT-fs (loop3): Unrecognized mount option "measure" or missing value
overlayfs: fs on './file0' does not support file handles, falling back to index=off,nfs_export=off.
overlayfs: missing 'lowerdir'
overlayfs: fs on './file0' does not support file handles, falling back to index=off,nfs_export=off.
overlayfs: fs on './file0' does not support file handles, falling back to index=off,nfs_export=off.
gfs2: invalid mount option: lr
gfs2: can't parse mount arguments
[U]
netlink: 12 bytes leftover after parsing attributes in process `syz-executor.4'.
FAT-fs (loop3): Unrecognized mount option "measure" or missing value
overlayfs: missing 'lowerdir'
overlayfs: fs on './file0' does not support file handles, falling back to index=off,nfs_export=off.
gfs2: invalid mount option: lr
gfs2: can't parse mount arguments
netlink: 12 bytes leftover after parsing attributes in process `syz-executor.4'.
netlink: 12 bytes leftover after parsing attributes in process `syz-executor.4'.
gfs2: invalid mount option: lr
gfs2: can't parse mount arguments
gfs2: invalid mount option: lr
gfs2: can't parse mount arguments
FAT-fs (loop3): Unrecognized mount option "measure" or missing value
overlayfs: missing 'lowerdir'
overlayfs: fs on './file0' does not support file handles, falling back to index=off,nfs_export=off.
list_del corruption, ffff88803d60f738->next is LIST_POISON1 (dead000000000100)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:45!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 10377 Comm: syz-executor.2 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__list_del_entry_valid.cold+0x23/0x4a lib/list_debug.c:45
Code: e8 11 43 f7 ff 0f 0b 48 89 ee 48 c7 c7 40 e4 b3 88 e8 00 43 f7 ff 0f 0b 4c 89 ea 48 89 ee 48 c7 c7 80 e3 b3 88 e8 ec 42 f7 ff <0f> 0b 4c 89 e2 48 89 ee 48 c7 c7 e0 e3 b3 88 e8 d8 42 f7 ff 0f 0b
list_del corruption, ffff8880484c7738->next is LIST_POISON1 (dead000000000100)
RSP: 0018:ffff88803d60f610 EFLAGS: 00010086
------------[ cut here ]------------
RAX: 000000000000004e RBX: ffff88803d60f720 RCX: 0000000000000000
kernel BUG at lib/list_debug.c:45!
RDX: 0000000000035119 RSI: ffffffff814dff01 RDI: ffffed1007ac1eb4
RBP: ffff88803d60f738 R08: 000000000000004e R09: 0000000000000000
R10: 0000000000000005 R11: ffffffff8c66501b R12: dead000000000200
R13: dead000000000100 R14: ffff88803d60f740 R15: 0000000000000007
FS: 00007f0ff2f3e700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff2d2b1eac CR3: 00000000b1642000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__list_del_entry include/linux/list.h:117 [inline]
list_del include/linux/list.h:125 [inline]
__remove_wait_queue include/linux/wait.h:184 [inline]
remove_wait_queue+0x2c/0x180 kernel/sched/wait.c:44
tipc_send_group_bcast+0x317/0xa10 net/tipc/socket.c:1022
__tipc_sendmsg+0xa2b/0x1320 net/tipc/socket.c:1314
tipc_sendmsg+0x4c/0x70 net/tipc/socket.c:1279
sock_sendmsg_nosec net/socket.c:651 [inline]
sock_sendmsg+0xc3/0x120 net/socket.c:661
___sys_sendmsg+0x3b3/0x8e0 net/socket.c:2227
__sys_sendmmsg+0x195/0x470 net/socket.c:2322
__do_sys_sendmmsg net/socket.c:2351 [inline]
__se_sys_sendmmsg net/socket.c:2348 [inline]
__x64_sys_sendmmsg+0x99/0x100 net/socket.c:2348
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f0ff45c8e99
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0ff2f3e168 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f0ff46dbf60 RCX: 00007f0ff45c8e99
RDX: 0000000000000092 RSI: 00000000200030c0 RDI: 0000000000000003
RBP: 00007f0ff4622ff1 R08: 0000000000000000 R09: 0000000000000000
R10: 9200000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffea065815f R14: 00007f0ff2f3e300 R15: 0000000000022000
Modules linked in:
---[ end trace 6758f07ddcda1d2f ]---
invalid opcode: 0000 [#2] PREEMPT SMP KASAN
RIP: 0010:__list_del_entry_valid.cold+0x23/0x4a lib/list_debug.c:45
CPU: 1 PID: 10389 Comm: syz-executor.2 Tainted: G D 4.19.211-syzkaller #0
Code: e8 11 43 f7 ff 0f 0b 48 89 ee 48 c7 c7 40 e4 b3 88 e8 00 43 f7 ff 0f 0b 4c 89 ea 48 89 ee 48 c7 c7 80 e3 b3 88 e8 ec 42 f7 ff <0f> 0b 4c 89 e2 48 89 ee 48 c7 c7 e0 e3 b3 88 e8 d8 42 f7 ff 0f 0b
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RSP: 0018:ffff88803d60f610 EFLAGS: 00010086
RIP: 0010:__list_del_entry_valid.cold+0x23/0x4a lib/list_debug.c:45
RAX: 000000000000004e RBX: ffff88803d60f720 RCX: 0000000000000000
Code: e8 11 43 f7 ff 0f 0b 48 89 ee 48 c7 c7 40 e4 b3 88 e8 00 43 f7 ff 0f 0b 4c 89 ea 48 89 ee 48 c7 c7 80 e3 b3 88 e8 ec 42 f7 ff <0f> 0b 4c 89 e2 48 89 ee 48 c7 c7 e0 e3 b3 88 e8 d8 42 f7 ff 0f 0b
RDX: 0000000000035119 RSI: ffffffff814dff01 RDI: ffffed1007ac1eb4
RSP: 0018:ffff8880484c7610 EFLAGS: 00010086
RBP: ffff88803d60f738 R08: 000000000000004e R09: 0000000000000000
RAX: 000000000000004e RBX: ffff8880484c7720 RCX: 0000000000000000
R10: 0000000000000005 R11: ffffffff8c66501b R12: dead000000000200
RDX: 0000000000040000 RSI: ffffffff814dff01 RDI: ffffed1009098eb4
R13: dead000000000100 R14: ffff88803d60f740 R15: 0000000000000007
RBP: ffff8880484c7738 R08: 000000000000004e R09: 0000000000000000
FS: 00007f0ff2f3e700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
R10: 0000000000000005 R11: ffffffff8c66505b R12: dead000000000200
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
R13: dead000000000100 R14: ffff8880484c7740 R15: 0000000000000007
CR2: 00007fff2d2b1eac CR3: 00000000b1642000 CR4: 00000000003406f0
FS: 00007f0ff2f1d700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
CR2: 0000001b30524000 CR3: 00000000b1642000 CR4: 00000000003406e0


---
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See https://goo.gl/tpsmEJ for more information about syzbot.
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y

console output: https://syzkaller.appspot.com/x/log.txt?x=12b895c7b00000

kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=d0bf53989411f8e4778f
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10bbab0bb00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d0bf53...@syzkaller.appspotmail.com

IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50

======================================================
WARNING: possible circular locking dependency detected
4.19.211-syzkaller #0 Not tainted
------------------------------------------------------

syz-executor.5/9591 is trying to acquire lock:
00000000ae16eb58 ((wq_completion)"dio/%s"sb->s_id){+.+.}, at: flush_workqueue+0xe8/0x13e0 kernel/workqueue.c:2658
wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50

but task is already holding lock:

00000000ff7b91c4 (&sb->s_type->i_mutex_key#10){+.+.}, at: inode_trylock include/linux/fs.h:768 [inline]
00000000ff7b91c4 (&sb->s_type->i_mutex_key#10){+.+.}, at: ext4_file_write_iter+0x21f/0xf20 fs/ext4/file.c:238

which lock already depends on the new lock.

ieee80211 phy12: Selected rate control algorithm 'minstrel_ht'

the existing dependency chain (in reverse order) is:

-> #2 (&sb->s_type->i_mutex_key#10){+.+.}:
inode_lock include/linux/fs.h:748 [inline]
__generic_file_fsync+0xb0/0x1f0 fs/libfs.c:989
ext4_sync_file+0xa35/0x1420 fs/ext4/fsync.c:118

IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
vfs_fsync_range+0x13a/0x220 fs/sync.c:197
wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50

generic_write_sync include/linux/fs.h:2750 [inline]
dio_complete+0x763/0xac0 fs/direct-io.c:329
process_one_work+0x864/0x1570 kernel/workqueue.c:2153

worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50

kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

-> #1 ((work_completion)(&dio->complete_work)){+.+.}:

1 lock held by syz-executor.5/9591:
#0: 00000000ff7b91c4 (&sb->s_type->i_mutex_key#10){+.+.}, at: inode_trylock include/linux/fs.h:768 [inline]
#0: 00000000ff7b91c4 (&sb->s_type->i_mutex_key#10){+.+.}, at: ext4_file_write_iter+0x21f/0xf20 fs/ext4/file.c:238

stack backtrace:
CPU: 0 PID: 9591 Comm: syz-executor.5 Not tainted 4.19.211-syzkaller #0

RIP: 0033:0x7f5eebbafe99

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 bc ff ff ff f7 d8 64 89 01 48

RSP: 002b:00007f5eeb325168 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1
RAX: ffffffffffffffda RBX: 00007f5eebcc2f60 RCX: 00007f5eebbafe99
RDX: 0000000020000540 RSI: 0000000000001801 RDI: 00007f5eebc9e000
RBP: 00007f5eebc09ff1 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000

R13: 00007ffd23fabd5f R14: 00007f5eeb325300 R15: 0000000000022000
IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready
IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready
wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
ieee80211 phy13: Selected rate control algorithm 'minstrel_ht'
wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready