=============================
WARNING: suspicious RCU usage
6.10.0-rc2-syzkaller #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
3 locks held by syz-executor.3/5394:
#0: ffffc90000858cb0 ((&p->forward_delay_timer)){+.-.}-{0:0}, at: call_timer_fn+0x11a/0x610 kernel/time/timer.c:1789
#1: ffff888047474cb8 (&br->lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#1: ffff888047474cb8 (&br->lock){+.-.}-{2:2}, at: br_forward_delay_timer_expired+0x4f/0x560 net/bridge/br_stp_timer.c:86
#2: ffffffff8dbb18e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
#2: ffffffff8dbb18e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
#2: ffffffff8dbb18e0 (rcu_read_lock){....}-{1:2}, at: br_mst_set_state+0x114/0x750 net/bridge/br_mst.c:105
stack backtrace:
CPU: 2 PID: 5394 Comm: syz-executor.3 Not tainted 6.10.0-rc2-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
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:preempt_count arch/x86/include/asm/preempt.h:26 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:write_comp_data+0x11/0x90 kernel/kcov.c:236
Code: cc cc 0f 1f 80 00 00 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 a9 00 01 ff 00 74 0f f6 c4 01 74 59 8b 82 1c
RSP: 0018:ffffc9000390f788 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffffea00014257c0 RCX: ffffffff81c46d85
RDX: ffff88801b8b2440 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000000
R13: ffffea00014257c0 R14: 0000000000000000 R15: ffffc9000390f9d0
folio_mapcount include/linux/mm.h:1273 [inline]
folio_mapped include/linux/mm.h:1291 [inline]
truncate_cleanup_folio+0x55/0x430 mm/truncate.c:174
truncate_inode_folio+0x3f/0x70 mm/truncate.c:194
shmem_undo_range+0x378/0x1160 mm/shmem.c:1001
shmem_truncate_range mm/shmem.c:1114 [inline]
shmem_evict_inode+0x3a3/0xbb0 mm/shmem.c:1242
evict+0x2ed/0x6c0 fs/inode.c:667
iput_final fs/inode.c:1741 [inline]
iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
iput+0x5c/0x80 fs/inode.c:1757
dentry_unlink_inode+0x295/0x480 fs/dcache.c:400
__dentry_kill+0x1d0/0x600 fs/dcache.c:603
dput.part.0+0x4b1/0x9b0 fs/dcache.c:845
dput+0x1f/0x30 fs/dcache.c:835
__fput+0x54e/0xbb0 fs/file_table.c:430
task_work_run+0x14e/0x250 kernel/task_work.c:180
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd9ad27cc4b
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007ffe14255960 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007fd9ad27cc4b
RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000003
RBP: 00007ffe14255a1c R08: 0000000000000000 R09: 00007ffe14255707
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000032
R13: 000000000002934b R14: 000000000002904f R15: 0000000000000010
bridge0: port 1(bridge_slave_0) entered learning state
bridge0: port 2(bridge_slave_1) entered learning state
----------------
Code disassembly (best guess):
0: cc int3
1: cc int3
2: 0f 1f 80 00 00 00 00 nopl 0x0(%rax)
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: 90 nop
13: 90 nop
14: 90 nop
15: 90 nop
16: 90 nop
17: 90 nop
18: 90 nop
19: 49 89 d2 mov %rdx,%r10
1c: 49 89 f8 mov %rdi,%r8
1f: 49 89 f1 mov %rsi,%r9
22: 65 48 8b 15 ff fa 75 mov %gs:0x7e75faff(%rip),%rdx # 0x7e75fb29
29: 7e
* 2a: 65 8b 05 00 fb 75 7e mov %gs:0x7e75fb00(%rip),%eax # 0x7e75fb31 <-- trapping instruction
31: a9 00 01 ff 00 test $0xff0100,%eax
36: 74 0f je 0x47
38: f6 c4 01 test $0x1,%ah
3b: 74 59 je 0x96
3d: 8b .byte 0x8b
3e: 82 .byte 0x82
3f: 1c .byte 0x1c