=============================
WARNING: suspicious RCU usage
6.10.0-rc2-syzkaller-00235-g8a92980606e3 #0 Not tainted
-----------------------------
net/bridge/br_private.h:1599 suspicious rcu_dereference_protected() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
7 locks held by kworker/1:7/5187:
#0: ffff888015480948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12bf/0x1b60 kernel/workqueue.c:3206
#1: ffffc9000421fd80 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x957/0x1b60 kernel/workqueue.c:3207
#2: ffff888061d5e250 (&devlink->lock_key#14){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x53/0xc80 drivers/net/netdevsim/dev.c:838
#3: ffff88805c5abce0 (&nsim_trap_data->trap_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#3: ffff88805c5abce0 (&nsim_trap_data->trap_lock){+.+.}-{2:2}, at: nsim_dev_trap_report drivers/net/netdevsim/dev.c:791 [inline]
#3: ffff88805c5abce0 (&nsim_trap_data->trap_lock){+.+.}-{2:2}, at: nsim_dev_trap_report_work+0x1c5/0xc80 drivers/net/netdevsim/dev.c:850
#4: ffffc90000a18cb0 ((&p->forward_delay_timer)){+.-.}-{0:0}, at: call_timer_fn+0x11a/0x610 kernel/time/timer.c:1789
#5: ffff88802e014cb8 (&br->lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#5: ffff88802e014cb8 (&br->lock){+.-.}-{2:2}, at: br_forward_delay_timer_expired+0x4f/0x560 net/bridge/br_stp_timer.c:86
#6: ffffffff8dbb1920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
#6: ffffffff8dbb1920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
#6: ffffffff8dbb1920 (rcu_read_lock){....}-{1:2}, at: br_mst_set_state+0x114/0x750 net/bridge/br_mst.c:105
stack backtrace:
CPU: 1 PID: 5187 Comm: kworker/1:7 Not tainted 6.10.0-rc2-syzkaller-00235-g8a92980606e3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: events nsim_dev_trap_report_work
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:114
lockdep_rcu_suspicious+0x20b/0x3b0 kernel/locking/lockdep.c:6712
nbp_vlan_group net/bridge/br_private.h:1599 [inline]
br_mst_set_state+0x5c8/0x750 net/bridge/br_mst.c:106
br_set_state+0x542/0x880 net/bridge/br_stp.c:47
br_forward_delay_timer_expired+0x311/0x560 net/bridge/br_stp_timer.c:88
call_timer_fn+0x1a0/0x610 kernel/time/timer.c:1792
expire_timers kernel/time/timer.c:1843 [inline]
__run_timers+0x74b/0xaf0 kernel/time/timer.c:2417
__run_timer_base kernel/time/timer.c:2428 [inline]
__run_timer_base kernel/time/timer.c:2421 [inline]
run_timer_base+0x111/0x190 kernel/time/timer.c:2437
run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2447
handle_softirqs+0x216/0x8f0 kernel/softirq.c:554
__do_softirq kernel/softirq.c:588 [inline]
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu kernel/softirq.c:637 [inline]
irq_exit_rcu+0xbb/0x120 kernel/softirq.c:649
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1043
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:write_comp_data+0x18/0x90 kernel/kcov.c:236
Code: 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 49 89 d2 49 89 f8 49 89 f1 65 48 8b 15 ff fa 75 7e 65 8b 05 00 fb 75 7e 00 01 ff 00 74 0f f6 c4 01 74 59 8b 82 1c 16 00 00 85 c0 74 4f
RSP: 0000:ffffc9000421f708 EFLAGS: 00000206
RAX: 0000000080000002 RBX: 0000000000000003 RCX: ffffffff813ce55e
RDX: ffff88807cfabc00 RSI: 0000000000000004 RDI: 0000000000000001
RBP: ffffffff8b29cae0 R08: 0000000000000001 R09: 0000000000000004
R10: 0000000000000001 R11: 0000000000000004 R12: 0000000000000001
R13: 0000000000000001 R14: 0000000000000003 R15: 0000000000000001
__sanitizer_cov_trace_switch+0x54/0x90 kernel/kcov.c:341
unwind_next_frame+0xebe/0x23a0 arch/x86/kernel/unwind_orc.c:641
arch_stack_walk+0x100/0x170 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
poison_slab_object+0xf7/0x160 mm/kasan/common.c:240
__kasan_slab_free+0x32/0x50 mm/kasan/common.c:256
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2195 [inline]
slab_free mm/slub.c:4436 [inline]
kmem_cache_free+0x12f/0x3a0 mm/slub.c:4511
kfree_skbmem+0x10e/0x200 net/core/skbuff.c:1131
__kfree_skb net/core/skbuff.c:1188 [inline]
consume_skb net/core/skbuff.c:1409 [inline]
consume_skb+0xdd/0x170 net/core/skbuff.c:1403
nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline]
nsim_dev_trap_report_work+0x878/0xc80 drivers/net/netdevsim/dev.c:850
process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231
process_scheduled_works kernel/workqueue.c:3312 [inline]
worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
bridge0: port 1(bridge_slave_0) entered learning state
bridge0: port 2(bridge_slave_1) entered learning state
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 90 nop
3: 90 nop
4: 90 nop
5: 90 nop
6: 90 nop
7: 90 nop
8: 90 nop
9: 90 nop
a: 90 nop
b: 90 nop
c: 90 nop
d: 90 nop
e: 90 nop
f: 90 nop
10: 90 nop
11: 90 nop
12: 49 89 d2 mov %rdx,%r10
15: 49 89 f8 mov %rdi,%r8
18: 49 89 f1 mov %rsi,%r9
1b: 65 48 8b 15 ff fa 75 mov %gs:0x7e75faff(%rip),%rdx # 0x7e75fb22
22: 7e
23: 65 8b 05 00 fb 75 7e mov %gs:0x7e75fb00(%rip),%eax # 0x7e75fb2a
* 2a: a9 00 01 ff 00 test $0xff0100,%eax <-- trapping instruction
2f: 74 0f je 0x40
31: f6 c4 01 test $0x1,%ah
34: 74 59 je 0x8f
36: 8b 82 1c 16 00 00 mov 0x161c(%rdx),%eax
3c: 85 c0 test %eax,%eax
3e: 74 4f je 0x8f