============================= WARNING: suspicious RCU usage 6.9.0-rc4-next-20240418-syzkaller #0 Not tainted ----------------------------- kernel/rcu/tree.c:276 Illegal rcu_softirq_qs() in RCU read-side critical section! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by ksoftirqd/1/24: #0: ffffffff8e333ae0 (rcu_read_lock_sched){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e333ae0 (rcu_read_lock_sched){....}-{1:2}, at: rcu_read_lock_sched include/linux/rcupdate.h:933 [inline] #0: ffffffff8e333ae0 (rcu_read_lock_sched){....}-{1:2}, at: pfn_valid include/linux/mmzone.h:2022 [inline] #0: ffffffff8e333ae0 (rcu_read_lock_sched){....}-{1:2}, at: __virt_addr_valid+0x183/0x520 arch/x86/mm/physaddr.c:65 stack backtrace: CPU: 1 PID: 24 Comm: ksoftirqd/1 Not tainted 6.9.0-rc4-next-20240418-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 lockdep_rcu_suspicious+0x221/0x340 kernel/locking/lockdep.c:6712 rcu_softirq_qs+0xd9/0x370 kernel/rcu/tree.c:273 __do_softirq+0x5fd/0x980 kernel/softirq.c:568 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline] sysvec_call_function_single+0xa3/0xc0 arch/x86/kernel/smp.c:266 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline] RIP: 0010:rcu_is_watching+0x5a/0xb0 kernel/rcu/tree.c:725 Code: f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 ec 15 7f 00 48 c7 c3 08 7d 03 00 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 75 22 8b 03 65 ff 0d b1 3c 87 7e 74 10 83 e0 04 c1 e8 02 5b RSP: 0018:ffffc900001e7a38 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: ffff8880b9537d08 RCX: ffff888017af0000 RDX: ffff888017af0000 RSI: ffffffff8c1f8ba0 RDI: ffffffff8c1f8b60 RBP: dffffc0000000000 R08: ffffffff81424074 R09: 1ffffffff25ef6b4 R10: dffffc0000000000 R11: fffffbfff25ef6b5 R12: 0000000072a15378 R13: 1ffff9200003cf64 R14: ffffffff8dd949e8 R15: dffffc0000000000 rcu_read_lock_sched include/linux/rcupdate.h:934 [inline] pfn_valid include/linux/mmzone.h:2022 [inline] __virt_addr_valid+0x1bd/0x520 arch/x86/mm/physaddr.c:65 kasan_addr_to_slab+0xd/0x80 mm/kasan/common.c:37 __kasan_record_aux_stack+0x11/0xc0 mm/kasan/generic.c:526 __call_rcu_common kernel/rcu/tree.c:3102 [inline] call_rcu+0x167/0xa70 kernel/rcu/tree.c:3206 context_switch kernel/sched/core.c:5411 [inline] __schedule+0x17f0/0x4a50 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 smpboot_thread_fn+0x61e/0xa30 kernel/smpboot.c:160 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 ---------------- Code disassembly (best guess): 0: f0 48 c1 e8 03 lock shr $0x3,%rax 5: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1) a: 74 08 je 0x14 c: 4c 89 f7 mov %r14,%rdi f: e8 ec 15 7f 00 call 0x7f1600 14: 48 c7 c3 08 7d 03 00 mov $0x37d08,%rbx 1b: 49 03 1e add (%r14),%rbx 1e: 48 89 d8 mov %rbx,%rax 21: 48 c1 e8 03 shr $0x3,%rax 25: 42 0f b6 04 38 movzbl (%rax,%r15,1),%eax * 2a: 84 c0 test %al,%al <-- trapping instruction 2c: 75 22 jne 0x50 2e: 8b 03 mov (%rbx),%eax 30: 65 ff 0d b1 3c 87 7e decl %gs:0x7e873cb1(%rip) # 0x7e873ce8 37: 74 10 je 0x49 39: 83 e0 04 and $0x4,%eax 3c: c1 e8 02 shr $0x2,%eax 3f: 5b pop %rbx