[syzbot] [mm?] inconsistent lock state in lru_gen_rotate_memcg

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 40f71e7cd3c6 Merge tag 'net-6.4-rc7' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1154eb17280000
kernel config: https://syzkaller.appspot.com/x/.config?x=b55c7ca2258f24ba
dashboard link: https://syzkaller.appspot.com/bug?extid=87c490fd2be656269b6a
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12acd517280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14276ecf280000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-40f71e7c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1d6d986d5baf/vmlinux-40f71e7c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/cb0c02dd7f64/bzImage-40f71e7c.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+87c490...@syzkaller.appspotmail.com

================================
WARNING: inconsistent lock state
6.4.0-rc6-syzkaller-00195-g40f71e7cd3c6 #0 Not tainted
--------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
syz-executor192/6901 [HC0[0]:SC1[1]:HE0:SE0] takes:
ffff88807ffdc728 (&pgdat->memcg_lru.lock){+.?.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline]
ffff88807ffdc728 (&pgdat->memcg_lru.lock){+.?.}-{2:2}, at: lru_gen_rotate_memcg+0x64/0xab0 mm/vmscan.c:4749
{SOFTIRQ-ON-W} state was registered at:
lock_acquire kernel/locking/lockdep.c:5705 [inline]
lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5670
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:350 [inline]
lru_gen_online_memcg+0x16b/0x5a0 mm/vmscan.c:4797
mem_cgroup_css_online+0x227/0x3b0 mm/memcontrol.c:5468
online_css+0xaf/0x2a0 kernel/cgroup/cgroup.c:5491
cgroup_init_subsys+0x46b/0x900 kernel/cgroup/cgroup.c:6022
cgroup_init+0xb83/0x1090 kernel/cgroup/cgroup.c:6106
start_kernel+0x398/0x490 init/main.c:1077
x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:556
x86_64_start_kernel+0xb3/0xc0 arch/x86/kernel/head64.c:537
secondary_startup_64_no_verify+0xf4/0xfb
irq event stamp: 1403
hardirqs last enabled at (1402): [<ffffffff81dc88cf>] mod_memcg_state include/linux/memcontrol.h:982 [inline]
hardirqs last enabled at (1402): [<ffffffff81dc88cf>] memcg_account_kmem+0x4f/0x80 mm/memcontrol.c:3094
hardirqs last disabled at (1403): [<ffffffff81dcc157>] uncharge_batch+0x1c7/0x560 mm/memcontrol.c:7142
softirqs last enabled at (1178): [<ffffffff880eb512>] rcu_read_unlock_bh include/linux/rcupdate.h:839 [inline]
softirqs last enabled at (1178): [<ffffffff880eb512>] __dev_queue_xmit+0x1df2/0x3b10 net/core/dev.c:4271
softirqs last disabled at (1253): [<ffffffff814cefd4>] invoke_softirq kernel/softirq.c:445 [inline]
softirqs last disabled at (1253): [<ffffffff814cefd4>] __irq_exit_rcu+0x114/0x190 kernel/softirq.c:650

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

CPU0
----
lock(&pgdat->memcg_lru.lock);
<Interrupt>
lock(&pgdat->memcg_lru.lock);

*** DEADLOCK ***

2 locks held by syz-executor192/6901:
#0: ffffffff8e10b9e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
#0: ffffffff8e10b9e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3e8/0xd50 net/core/rtnetlink.c:6414
#1: ffffffff8c795fe0 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2104 [inline]
#1: ffffffff8c795fe0 (rcu_callback){....}-{0:0}, at: rcu_core+0x791/0x1ad0 kernel/rcu/tree.c:2377

stack backtrace:
CPU: 3 PID: 6901 Comm: syz-executor192 Not tainted 6.4.0-rc6-syzkaller-00195-g40f71e7cd3c6 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
print_usage_bug kernel/locking/lockdep.c:3949 [inline]
valid_state kernel/locking/lockdep.c:3991 [inline]
mark_lock_irq kernel/locking/lockdep.c:4194 [inline]
mark_lock.part.0+0x1110/0x1970 kernel/locking/lockdep.c:4656
mark_lock kernel/locking/lockdep.c:4620 [inline]
mark_usage kernel/locking/lockdep.c:4545 [inline]
__lock_acquire+0x1227/0x5f30 kernel/locking/lockdep.c:5042
lock_acquire kernel/locking/lockdep.c:5705 [inline]
lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5670
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:350 [inline]
lru_gen_rotate_memcg+0x64/0xab0 mm/vmscan.c:4749
lru_gen_soft_reclaim+0x62/0x70 mm/vmscan.c:4852
uncharge_batch+0x2be/0x560 mm/memcontrol.c:7145
__mem_cgroup_uncharge+0x11f/0x290 mm/memcontrol.c:7221
mem_cgroup_uncharge include/linux/memcontrol.h:698 [inline]
__folio_put_small mm/swap.c:105 [inline]
__folio_put+0xb6/0x140 mm/swap.c:129
folio_put include/linux/mm.h:1430 [inline]
put_page include/linux/mm.h:1499 [inline]
free_page_and_swap_cache+0x257/0x2c0 mm/swap_state.c:305
__tlb_remove_table arch/x86/include/asm/tlb.h:34 [inline]
__tlb_remove_table_free mm/mmu_gather.c:153 [inline]
tlb_remove_table_rcu+0x89/0xe0 mm/mmu_gather.c:208
rcu_do_batch kernel/rcu/tree.c:2115 [inline]
rcu_core+0x806/0x1ad0 kernel/rcu/tree.c:2377
__do_softirq+0x1d4/0x905 kernel/softirq.c:571
invoke_softirq kernel/softirq.c:445 [inline]
__irq_exit_rcu+0x114/0x190 kernel/softirq.c:650
irq_exit_rcu+0x9/0x20 kernel/softirq.c:662
sysvec_apic_timer_interrupt+0x97/0xc0 arch/x86/kernel/apic/apic.c:1106
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:__sanitizer_cov_trace_pc+0x3b/0x70 kernel/kcov.c:207
Code: 81 e1 00 01 00 00 65 48 8b 14 25 00 bc 03 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 0c 16 00 00 85 c0 74 2b 8b 82 e8 15 00 00 <83> f8 02 75 20 48 8b 8a f0 15 00 00 8b 92 ec 15 00 00 48 8b 01 48
RSP: 0018:ffffc9000420ecf8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000064 RCX: 0000000000000000
RDX: ffff888044f60380 RSI: ffffffff8a021a9b RDI: 0000000000000001
RBP: ffff88802b6d6004 R08: 0000000000000001 R09: 000000000000006e
R10: 0000000000000064 R11: 0000000000094001 R12: ffff888054ea8005
R13: 00000000ffffffff R14: 00000000ffffffff R15: dffffc0000000000
vsscanf+0x34b/0x2600 lib/vsprintf.c:3518
sscanf+0xbf/0xf0 lib/vsprintf.c:3716
__dev_alloc_name net/core/dev.c:1065 [inline]
dev_alloc_name_ns+0x343/0x610 net/core/dev.c:1099
dev_get_valid_name+0x69/0x170 net/core/dev.c:1134
register_netdevice+0x3ba/0x1640 net/core/dev.c:10006
veth_newlink+0x352/0x9d0 drivers/net/veth.c:1897
rtnl_newlink_create net/core/rtnetlink.c:3465 [inline]
__rtnl_newlink+0x10c2/0x1840 net/core/rtnetlink.c:3682
rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3695
rtnetlink_rcv_msg+0x43d/0xd50 net/core/rtnetlink.c:6417
netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2546
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x925/0xe30 net/netlink/af_netlink.c:1913
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg+0xde/0x190 net/socket.c:747
____sys_sendmsg+0x71c/0x900 net/socket.c:2503
___sys_sendmsg+0x110/0x1b0 net/socket.c:2557
__sys_sendmsg+0xf7/0x1c0 net/socket.c:2586
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f0ee7a7d049
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 16 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:00007ffe607e0d88 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f0ee7a7d049
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000246 R12: 00007ffe607e0db8
R13: 00007ffe607e0dd0 R14: 00007ffe607e0e10 R15: 00000000000006cd
</TASK>
----------------
Code disassembly (best guess):
0: 81 e1 00 01 00 00 and $0x100,%ecx
6: 65 48 8b 14 25 00 bc mov %gs:0x3bc00,%rdx
d: 03 00
f: a9 00 01 ff 00 test $0xff0100,%eax
14: 74 0e je 0x24
16: 85 c9 test %ecx,%ecx
18: 74 35 je 0x4f
1a: 8b 82 0c 16 00 00 mov 0x160c(%rdx),%eax
20: 85 c0 test %eax,%eax
22: 74 2b je 0x4f
24: 8b 82 e8 15 00 00 mov 0x15e8(%rdx),%eax
* 2a: 83 f8 02 cmp $0x2,%eax <-- trapping instruction
2d: 75 20 jne 0x4f
2f: 48 8b 8a f0 15 00 00 mov 0x15f0(%rdx),%rcx
36: 8b 92 ec 15 00 00 mov 0x15ec(%rdx),%edx
3c: 48 8b 01 mov (%rcx),%rax
3f: 48 rex.W


---
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[Andrew Morton]

On Mon, 19 Jun 2023 08:14:35 -0700 syzbot <syzbot+87c490...@syzkaller.appspotmail.com> wrote:

> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 40f71e7cd3c6 Merge tag 'net-6.4-rc7' of git://git.kernel.o..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=1154eb17280000
> kernel config: https://syzkaller.appspot.com/x/.config?x=b55c7ca2258f24ba

CONFIG_LRU_GEN=y
CONFIG_LRU_GEN_ENABLED=y

Maybe caused by TJ's series?

https://lkml.kernel.org/r/20230522112058.2...@google.com
https://lkml.kernel.org/r/20230522112058.2...@google.com
https://lkml.kernel.org/r/20230522112058.2...@google.com
https://lkml.kernel.org/r/20230522112058.2...@google.com

[Yu Zhao]

On Mon, Jun 19, 2023 at 12:06 PM Andrew Morton
<ak...@linux-foundation.org> wrote:
>
> On Mon, 19 Jun 2023 08:14:35 -0700 syzbot <syzbot+87c490...@syzkaller.appspotmail.com> wrote:
>
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit: 40f71e7cd3c6 Merge tag 'net-6.4-rc7' of git://git.kernel.o..
> > git tree: upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=1154eb17280000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=b55c7ca2258f24ba
>
> CONFIG_LRU_GEN=y
> CONFIG_LRU_GEN_ENABLED=y
>
> Maybe caused by TJ's series?

No, it's caused by my original series. I'll fix it shortly.