bisecting fixing commit since 8bac50406cca10a219aa899243d49c57ddaf7c5b
building syzkaller on 3334d684ce742ce58ad66b7dcb7a6d4da5185796
testing commit 8bac50406cca10a219aa899243d49c57ddaf7c5b with gcc (GCC) 8.1.0
kernel signature: 613a2722647de81929717769ff73f628c85865cdaf07eb16ee6c912a54bbef6c
all runs: crashed: WARNING: ODEBUG bug in free_tcf
testing current HEAD a41ba30d9df20fe141c92aacbb56b6b077f19716
testing commit a41ba30d9df20fe141c92aacbb56b6b077f19716 with gcc (GCC) 8.1.0
kernel signature: 11bdf2becfb6a03030aca119152685ee506e6f93ac3ac95270dd4d393ab141bf
all runs: crashed: WARNING: ODEBUG bug in free_tcf
revisions tested: 2, total time: 23m58.679342387s (build: 16m26.045270949s, test: 6m29.207758019s)
the crash still happens on HEAD
commit msg: Linux 4.14.181
crash: WARNING: ODEBUG bug in free_tcf
IPv6: ADDRCONF(NETDEV_UP): veth0_to_batadv: link is not ready
IPv6: ADDRCONF(NETDEV_UP): vxcan0: link is not ready
ODEBUG: free active (active state 1) object type: rcu_head hint:           (null)
------------[ cut here ]------------
WARNING: CPU: 0 PID: 7671 at lib/debugobjects.c:290 debug_print_object.cold.13+0xa7/0xdb lib/debugobjects.c:287
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 7671 Comm: syz-executor.2 Not tainted 4.14.181-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xf7/0x13b lib/dump_stack.c:58
 panic+0x1b0/0x358 kernel/panic.c:183
 __warn.cold.8+0x25/0x2c kernel/panic.c:547
 report_bug+0x1a4/0x1f3 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 do_error_trap+0x1bd/0x310 arch/x86/kernel/traps.c:295
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:964
RIP: 0010:debug_print_object.cold.13+0xa7/0xdb lib/debugobjects.c:287
RSP: 0018:ffff8880a7dbf000 EFLAGS: 00010086
RAX: 0000000000000051 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000051 RSI: ffffffff87043880 RDI: ffffed1014fb7df7
RBP: ffff8880a7dbf028 R08: 0000000000000000 R09: 0000000000000000
R10: fffffbfff13458ef R11: dffffc0000000000 R12: ffffffff86cb6e80
R13: 0000000000000000 R14: 0000000000000001 R15: ffff8880a6570410
 __debug_check_no_obj_freed lib/debugobjects.c:747 [inline]
 debug_check_no_obj_freed+0x506/0x930 lib/debugobjects.c:776
 kfree+0xbd/0x270 mm/slab.c:3814
 free_tcf+0x114/0x160 net/sched/act_api.c:73
 tcf_idr_remove net/sched/act_api.c:82 [inline]
 __tcf_idr_release+0x17f/0x1c0 net/sched/act_api.c:101
 tcf_idr_release include/net/act_api.h:150 [inline]
 tcf_sample_init+0x80f/0x920 net/sched/act_sample.c:80
 tcf_action_init_1+0x51a/0xb10 net/sched/act_api.c:682
 tcf_action_init+0x13b/0x460 net/sched/act_api.c:751
 tcf_action_add net/sched/act_api.c:1079 [inline]
 tc_ctl_action+0x3c4/0x573 net/sched/act_api.c:1131
 rtnetlink_rcv_msg+0x34c/0x9e0 net/core/rtnetlink.c:4315
 netlink_rcv_skb+0x133/0x370 net/netlink/af_netlink.c:2433
 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4327
 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
 netlink_unicast+0x40b/0x600 net/netlink/af_netlink.c:1313
 netlink_sendmsg+0x730/0xbd0 net/netlink/af_netlink.c:1878
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0xf0 net/socket.c:656
 ___sys_sendmsg+0x625/0x920 net/socket.c:2062
 __sys_sendmsg+0xc1/0x140 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0xd/0x20 net/socket.c:2103
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45b349
RSP: 002b:00007f18f8450c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f18f84516d4 RCX: 000000000045b349
RDX: 0000000000000000 RSI: 0000000020002980 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000099f R14: 00000000004cb163 R15: 000000000075bf2c

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