Re: [syzbot] WARNING: ODEBUG bug in route4_destroy

[syzbot <syzbot+2e3efb5eb71cb5075ba7@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING: ODEBUG bug in route4_destroy

------------[ cut here ]------------
ODEBUG: activate active (active state 1) object type: rcu_head hint: 0x0
WARNING: CPU: 0 PID: 4132 at lib/debugobjects.c:502 debug_print_object+0x16e/0x250 lib/debugobjects.c:502
Modules linked in:
CPU: 0 PID: 4132 Comm: syz-executor.0 Not tainted 5.19.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:502
Code: ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 af 00 00 00 48 8b 14 dd e0 c5 27 8a 4c 89 ee 48 c7 c7 c0 b9 27 8a e8 f6 1b 30 05 <0f> 0b 83 05 35 22 c5 09 01 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e c3
RSP: 0018:ffffc9000339efb0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: ffff8880221057c0 RSI: ffffffff815fcd08 RDI: fffff52000673de8
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000001 R12: ffffffff89cde060
R13: ffffffff8a27c080 R14: 0000000000000000 R15: ffffffff89cde060
FS:  00007fd48e521700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd48e500718 CR3: 000000001b202000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 debug_object_activate+0x2da/0x3e0 lib/debugobjects.c:674
 debug_rcu_head_queue kernel/rcu/rcu.h:178 [inline]
 call_rcu+0x2c/0x790 kernel/rcu/tree.c:3111
 queue_rcu_work+0x82/0xa0 kernel/workqueue.c:1774
 route4_queue_work net/sched/cls_route.c:272 [inline]
 route4_destroy+0x4b9/0x9a0 net/sched/cls_route.c:299
 tcf_proto_destroy+0x6a/0x2d0 net/sched/cls_api.c:314
 tcf_proto_put+0x8c/0xc0 net/sched/cls_api.c:326
 tcf_chain_flush+0x21a/0x360 net/sched/cls_api.c:632
 tcf_block_flush_all_chains net/sched/cls_api.c:1034 [inline]
 __tcf_block_put+0x15a/0x510 net/sched/cls_api.c:1196
 tcf_block_put_ext net/sched/cls_api.c:1396 [inline]
 tcf_block_put+0xb3/0x100 net/sched/cls_api.c:1411
 drr_destroy_qdisc+0x44/0x1d0 net/sched/sch_drr.c:455
 qdisc_destroy+0xc4/0x4e0 net/sched/sch_generic.c:1067
 qdisc_put+0xcd/0xe0 net/sched/sch_generic.c:1086
 notify_and_destroy net/sched/sch_api.c:1012 [inline]
 qdisc_graft+0xeb1/0x1270 net/sched/sch_api.c:1084
 tc_modify_qdisc+0xbb7/0x1a00 net/sched/sch_api.c:1671
 rtnetlink_rcv_msg+0x43a/0xc90 net/core/rtnetlink.c:6089
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:734
 ____sys_sendmsg+0x6eb/0x810 net/socket.c:2492
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2546
 __sys_sendmsg net/socket.c:2575 [inline]
 __do_sys_sendmsg net/socket.c:2584 [inline]
 __se_sys_sendmsg net/socket.c:2582 [inline]
 __x64_sys_sendmsg+0x132/0x220 net/socket.c:2582
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x4665f9
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:00007fd48e521188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665f9
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000004
RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffefe84a09f R14: 00007fd48e521300 R15: 0000000000022000
 </TASK>


Tested on:

commit:         018ab4fa netfs: fix up netfs_inode_init() docbook comm..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=169cf608080000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f21890d74080ef72
dashboard link: https://syzkaller.appspot.com/bug?extid=2e3efb5eb71cb5075ba7
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Note: no patches were applied.