====================================================== WARNING: possible circular locking dependency detected 6.8.0-syzkaller-05236-g443574b03387 #0 Not tainted ------------------------------------------------------ syz-executor.2/5452 is trying to acquire lock: ffff8880b9538528 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b9538528 (lock#10){+.+.}-{2:2}, at: __mmap_lock_do_trace_start_locking+0x83/0x5f0 mm/mmap_lock.c:230 but task is already holding lock: ffff8880b953e158 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 raw_spin_rq_lock kernel/sched/sched.h:1385 [inline] rq_lock kernel/sched/sched.h:1699 [inline] task_fork_fair+0x61/0x1e0 kernel/sched/fair.c:12629 sched_cgroup_fork+0x37c/0x410 kernel/sched/core.c:4845 copy_process+0x2217/0x3df0 kernel/fork.c:2498 kernel_clone+0x21e/0x8d0 kernel/fork.c:2796 user_mode_thread+0x132/0x1a0 kernel/fork.c:2874 rest_init+0x27/0x300 init/main.c:695 arch_call_rest_init+0xe/0x10 init/main.c:831 start_kernel+0x47a/0x500 init/main.c:1077 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:509 x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:490 common_startup_64+0x13e/0x147 -> #1 (&p->pi_lock){-.-.}-{2:2}: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:553 [inline] try_to_wake_up+0xb0/0x1470 kernel/sched/core.c:4262 rcu_read_unlock_special+0x3db/0x550 kernel/rcu/tree_plugin.h:655 __rcu_read_unlock+0xa1/0x110 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:782 [inline] get_mem_cgroup_from_mm+0x1a3/0x2a0 mm/memcontrol.c:1112 get_mm_memcg_path+0x1b/0x600 mm/mmap_lock.c:202 __mmap_lock_do_trace_start_locking+0x134/0x5f0 mm/mmap_lock.c:230 __mmap_lock_trace_start_locking include/linux/mmap_lock.h:29 [inline] mmap_read_trylock include/linux/mmap_lock.h:164 [inline] get_mmap_lock_carefully mm/memory.c:5497 [inline] lock_mm_and_find_vma+0x1f1/0x2f0 mm/memory.c:5557 do_user_addr_fault arch/x86/mm/fault.c:1385 [inline] handle_page_fault arch/x86/mm/fault.c:1505 [inline] exc_page_fault+0x1a9/0x890 arch/x86/mm/fault.c:1563 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 rep_movs_alternative+0x4a/0x70 arch/x86/lib/copy_user_64.S:65 copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:125 [inline] copy_from_user_iter lib/iov_iter.c:55 [inline] iterate_ubuf include/linux/iov_iter.h:29 [inline] iterate_and_advance2 include/linux/iov_iter.h:245 [inline] iterate_and_advance include/linux/iov_iter.h:271 [inline] __copy_from_iter lib/iov_iter.c:249 [inline] _copy_from_iter+0x257/0x1cf0 lib/iov_iter.c:260 copy_from_iter include/linux/uio.h:204 [inline] copy_from_iter_full include/linux/uio.h:211 [inline] skb_do_copy_data_nocache include/net/sock.h:2231 [inline] skb_copy_to_page_nocache include/net/sock.h:2257 [inline] kcm_sendmsg+0xcca/0x27c0 net/kcm/kcmsock.c:858 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 sock_write_iter+0x2dd/0x400 net/socket.c:1160 call_write_iter include/linux/fs.h:2108 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa84/0xcb0 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 -> #0 (lock#10){+.+.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_start_locking+0x9c/0x5f0 mm/mmap_lock.c:230 __mmap_lock_trace_start_locking include/linux/mmap_lock.h:29 [inline] mmap_read_trylock include/linux/mmap_lock.h:164 [inline] stack_map_get_build_id_offset+0x98d/0x9d0 kernel/bpf/stackmap.c:141 __bpf_get_stack+0x4ad/0x5a0 kernel/bpf/stackmap.c:449 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1985 [inline] bpf_get_stack_raw_tp+0x1a3/0x240 kernel/trace/bpf_trace.c:1975 bpf_prog_5c8cb7646b59f521+0x42/0x46 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run2+0x204/0x420 kernel/trace/bpf_trace.c:2420 trace_tlb_flush+0xfa/0x120 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x7cb/0xae0 context_switch kernel/sched/core.c:5393 [inline] __schedule+0x1054/0x4a20 kernel/sched/core.c:6736 __schedule_loop kernel/sched/core.c:6813 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6828 exit_to_user_mode_loop kernel/entry/common.c:96 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] irqentry_exit_to_user_mode+0xe7/0x270 kernel/entry/common.c:225 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 other info that might help us debug this: Chain exists of: lock#10 --> &p->pi_lock --> &rq->__lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->__lock); lock(&p->pi_lock); lock(&rq->__lock); lock(lock#10); *** DEADLOCK *** 2 locks held by syz-executor.2/5452: #0: ffff8880b953e158 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 #1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] #1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x114/0x420 kernel/trace/bpf_trace.c:2420 stack backtrace: CPU: 1 PID: 5452 Comm: syz-executor.2 Not tainted 6.8.0-syzkaller-05236-g443574b03387 #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+0x1e7/0x2e0 lib/dump_stack.c:106 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_start_locking+0x9c/0x5f0 mm/mmap_lock.c:230 __mmap_lock_trace_start_locking include/linux/mmap_lock.h:29 [inline] mmap_read_trylock include/linux/mmap_lock.h:164 [inline] stack_map_get_build_id_offset+0x98d/0x9d0 kernel/bpf/stackmap.c:141 __bpf_get_stack+0x4ad/0x5a0 kernel/bpf/stackmap.c:449 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1985 [inline] bpf_get_stack_raw_tp+0x1a3/0x240 kernel/trace/bpf_trace.c:1975 bpf_prog_5c8cb7646b59f521+0x42/0x46 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run2+0x204/0x420 kernel/trace/bpf_trace.c:2420 trace_tlb_flush+0xfa/0x120 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x7cb/0xae0 context_switch kernel/sched/core.c:5393 [inline] __schedule+0x1054/0x4a20 kernel/sched/core.c:6736 __schedule_loop kernel/sched/core.c:6813 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6828 exit_to_user_mode_loop kernel/entry/common.c:96 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] irqentry_exit_to_user_mode+0xe7/0x270 kernel/entry/common.c:225 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0033:0x7fe38f639ba5 Code: Unable to access opcode bytes at 0x7fe38f639b7b. RSP: 002b:00007ffe0d7da5f0 EFLAGS: 00000a87 RAX: 00000000984f6378 RBX: 00007fe38f7ac018 RCX: 0000000000000415 RDX: ffffffff81408dcc RSI: 0000000080000000 RDI: 00000000984f6378 RBP: 0000000081408000 R08: 0000001b31220000 R09: 0000000000000dcd R10: 0000000081372dd1 R11: 0000000000000000 R12: 0000000000000415 R13: 0000000000000001 R14: 00007fe38f7a0000 R15: ffffffff81408dcc