====================================================== WARNING: possible circular locking dependency detected 5.15.163-syzkaller #0 Not tainted ------------------------------------------------------ syz.1.1388/7658 is trying to acquire lock: ffff88813fe227e8 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xae/0x1300 kernel/sched/core.c:4030 but task is already holding lock: ffff8880b9a35bb8 (lock#9){+.+.}-{2:2}, at: local_lock_acquire+0xd/0x170 include/linux/local_lock_internal.h:28 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (lock#9){+.+.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 local_lock_acquire+0x29/0x170 include/linux/local_lock_internal.h:29 __mmap_lock_do_trace_acquire_returned+0x7c/0x340 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:137 [inline] stack_map_get_build_id_offset+0x612/0x930 kernel/bpf/stackmap.c:185 __bpf_get_stack+0x495/0x570 kernel/bpf/stackmap.c:496 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1490 [inline] bpf_get_stack_raw_tp+0x1b2/0x220 kernel/trace/bpf_trace.c:1480 0xffffffffa003c146 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run2+0x19e/0x340 kernel/trace/bpf_trace.c:1917 trace_tlb_flush+0xed/0x110 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x748/0xa30 context_switch kernel/sched/core.c:5016 [inline] __schedule+0x1167/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_hrtimeout_range_clock+0x2b3/0x4a0 kernel/time/hrtimer.c:2308 ep_poll+0x1bc3/0x1e90 fs/eventpoll.c:1913 do_epoll_wait+0x1ae/0x220 fs/eventpoll.c:2291 __do_sys_epoll_wait fs/eventpoll.c:2303 [inline] __se_sys_epoll_wait fs/eventpoll.c:2298 [inline] __x64_sys_epoll_wait+0x253/0x2a0 fs/eventpoll.c:2298 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #1 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:368 raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 raw_spin_rq_lock kernel/sched/sched.h:1326 [inline] rq_lock kernel/sched/sched.h:1621 [inline] task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11495 sched_cgroup_fork+0x2d3/0x330 kernel/sched/core.c:4466 copy_process+0x224a/0x3ef0 kernel/fork.c:2320 kernel_clone+0x210/0x960 kernel/fork.c:2604 kernel_thread+0x168/0x1e0 kernel/fork.c:2656 rest_init+0x21/0x330 init/main.c:706 start_kernel+0x48c/0x540 init/main.c:1140 secondary_startup_64_no_verify+0xb1/0xbb -> #0 (&p->pi_lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 try_to_wake_up+0xae/0x1300 kernel/sched/core.c:4030 rcu_read_unlock_special+0x3aa/0x520 kernel/rcu/tree_plugin.h:650 __rcu_read_unlock+0x92/0x100 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:771 [inline] put_memcg_path_buf+0xde/0x100 mm/mmap_lock.c:153 __mmap_lock_do_trace_acquire_returned+0x12f/0x340 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:137 [inline] do_user_addr_fault arch/x86/mm/fault.c:1298 [inline] handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x564/0x700 arch/x86/mm/fault.c:1501 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568 __get_user_nocheck_1+0x6/0x10 arch/x86/lib/getuser.S:103 fault_in_readable+0x172/0x2e0 mm/gup.c:1801 fault_in_iov_iter_readable+0x14a/0x1d0 lib/iov_iter.c:460 generic_perform_write+0x1c9/0x5b0 mm/filemap.c:3775 __generic_file_write_iter+0x243/0x4f0 mm/filemap.c:3912 generic_file_write_iter+0xa7/0x1b0 mm/filemap.c:3944 call_write_iter include/linux/fs.h:2172 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0xacd/0xe50 fs/read_write.c:594 ksys_write+0x1a2/0x2c0 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Chain exists of: &p->pi_lock --> &rq->__lock --> lock#9 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock#9); lock(&rq->__lock); lock(lock#9); lock(&p->pi_lock); *** DEADLOCK *** 6 locks held by syz.1.1388/7658: #0: ffff8880232145f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2cb/0x380 fs/file.c:1088 #1: ffff88807d0f6460 (sb_writers#3){.+.+}-{0:0}, at: vfs_write+0x29a/0xe50 fs/read_write.c:590 #2: ffff888059ecdfc0 (&sb->s_type->i_mutex_key#8){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline] #2: ffff888059ecdfc0 (&sb->s_type->i_mutex_key#8){+.+.}-{3:3}, at: generic_file_write_iter+0x7c/0x1b0 mm/filemap.c:3941 #3: ffff8880193a4728 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #3: ffff8880193a4728 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault arch/x86/mm/fault.c:1298 [inline] #3: ffff8880193a4728 (&mm->mmap_lock){++++}-{3:3}, at: handle_page_fault arch/x86/mm/fault.c:1445 [inline] #3: ffff8880193a4728 (&mm->mmap_lock){++++}-{3:3}, at: exc_page_fault+0x181/0x700 arch/x86/mm/fault.c:1501 #4: ffff8880b9a35bb8 (lock#9){+.+.}-{2:2}, at: local_lock_acquire+0xd/0x170 include/linux/local_lock_internal.h:28 #5: ffffffff8c91fb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 stack backtrace: CPU: 0 PID: 7658 Comm: syz.1.1388 Not tainted 5.15.163-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 try_to_wake_up+0xae/0x1300 kernel/sched/core.c:4030 rcu_read_unlock_special+0x3aa/0x520 kernel/rcu/tree_plugin.h:650 __rcu_read_unlock+0x92/0x100 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:771 [inline] put_memcg_path_buf+0xde/0x100 mm/mmap_lock.c:153 __mmap_lock_do_trace_acquire_returned+0x12f/0x340 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:137 [inline] do_user_addr_fault arch/x86/mm/fault.c:1298 [inline] handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x564/0x700 arch/x86/mm/fault.c:1501 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568 RIP: 0010:__get_user_nocheck_1+0x6/0x10 arch/x86/lib/getuser.S:124 Code: d0 73 64 48 19 d2 48 21 d0 0f 01 cb 48 8b 10 31 c0 0f 01 ca c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 0f 01 cb 0f ae e8 <0f> b6 10 31 c0 0f 01 ca c3 90 0f 01 cb 0f ae e8 0f b7 10 31 c0 0f RSP: 0018:ffffc90002f179b8 EFLAGS: 00050287 RAX: 0000000020016000 RBX: 0000000020015180 RCX: 0000000000040000 RDX: ffffc900036fb000 RSI: 0000000000008540 RDI: 0000000000008541 RBP: ffffc90002f17a78 R08: ffffffff81b72a86 R09: fffff9400038c88f R10: 0000000000000000 R11: dffffc0000000001 R12: 00000000ffffffff R13: 0000000020016000 R14: 0000000020017000 R15: 0000000000000000 fault_in_readable+0x172/0x2e0 mm/gup.c:1801 fault_in_iov_iter_readable+0x14a/0x1d0 lib/iov_iter.c:460 generic_perform_write+0x1c9/0x5b0 mm/filemap.c:3775 __generic_file_write_iter+0x243/0x4f0 mm/filemap.c:3912 generic_file_write_iter+0xa7/0x1b0 mm/filemap.c:3944 call_write_iter include/linux/fs.h:2172 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0xacd/0xe50 fs/read_write.c:594 ksys_write+0x1a2/0x2c0 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fc52c1cff19 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc52a650048 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fc52c35ff60 RCX: 00007fc52c1cff19 RDX: 0000000000040010 RSI: 0000000020000180 RDI: 0000000000000007 RBP: 00007fc52c23ee68 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fc52c35ff60 R15: 00007ffdbe90ac88 ---------------- Code disassembly (best guess): 0: d0 73 64 shlb 0x64(%rbx) 3: 48 19 d2 sbb %rdx,%rdx 6: 48 21 d0 and %rdx,%rax 9: 0f 01 cb stac c: 48 8b 10 mov (%rax),%rdx f: 31 c0 xor %eax,%eax 11: 0f 01 ca clac 14: c3 ret 15: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 1c: 00 00 00 1f: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 24: 0f 01 cb stac 27: 0f ae e8 lfence * 2a: 0f b6 10 movzbl (%rax),%edx <-- trapping instruction 2d: 31 c0 xor %eax,%eax 2f: 0f 01 ca clac 32: c3 ret 33: 90 nop 34: 0f 01 cb stac 37: 0f ae e8 lfence 3a: 0f b7 10 movzwl (%rax),%edx 3d: 31 c0 xor %eax,%eax 3f: 0f .byte 0xf