====================================================== WARNING: possible circular locking dependency detected 6.11.0-rc5-syzkaller #0 Not tainted ------------------------------------------------------ syz.2.827/8984 is trying to acquire lock: ffff88807ffdbce0 (&pgdat->kswapd_wait){....}-{2:2}, at: __wake_up_common_lock kernel/sched/wait.c:105 [inline] ffff88807ffdbce0 (&pgdat->kswapd_wait){....}-{2:2}, at: __wake_up+0x1c/0x60 kernel/sched/wait.c:127 but task is already holding lock: ffff88802f5771f8 (&trie->lock){..-.}-{2:2}, at: trie_update_elem+0xc8/0xe00 kernel/bpf/lpm_trie.c:333 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&trie->lock){..-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 trie_delete_elem+0xb0/0x820 kernel/bpf/lpm_trie.c:462 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:2010 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2251 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:682 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2406 [inline] bpf_trace_run4+0x360/0x5a0 kernel/trace/bpf_trace.c:2449 __bpf_trace_sched_switch+0x13e/0x190 include/trace/events/sched.h:222 __traceiter_sched_switch+0x6c/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x17cf/0x5490 kernel/sched/core.c:6526 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6621 futex_wait_queue+0xfc/0x1f0 kernel/futex/waitwake.c:370 __futex_wait+0x291/0x3c0 kernel/futex/waitwake.c:669 futex_wait+0xe9/0x380 kernel/futex/waitwake.c:697 do_futex+0x22b/0x350 kernel/futex/syscalls.c:102 __do_sys_futex kernel/futex/syscalls.c:179 [inline] __se_sys_futex kernel/futex/syscalls.c:160 [inline] __x64_sys_futex+0x1e1/0x4c0 kernel/futex/syscalls.c:160 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&rq->__lock){-.-.}-{2:2}: _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:560 raw_spin_rq_lock kernel/sched/sched.h:1415 [inline] rq_lock kernel/sched/sched.h:1714 [inline] task_fork_fair+0x73/0x250 kernel/sched/fair.c:12710 sched_cgroup_fork+0x3cf/0x510 kernel/sched/core.c:4633 copy_process+0x43fa/0x8e90 kernel/fork.c:2502 kernel_clone+0xfd/0x960 kernel/fork.c:2800 user_mode_thread+0xb4/0xf0 kernel/fork.c:2878 rest_init+0x23/0x2b0 init/main.c:712 start_kernel+0x3df/0x4c0 init/main.c:1103 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x148 -> #1 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline] try_to_wake_up+0x9a/0x13e0 kernel/sched/core.c:4051 autoremove_wake_function+0x16/0x150 kernel/sched/wait.c:384 __wake_up_common+0x131/0x1e0 kernel/sched/wait.c:89 __wake_up_common_lock kernel/sched/wait.c:106 [inline] __wake_up+0x31/0x60 kernel/sched/wait.c:127 wakeup_kswapd+0x45e/0x640 mm/vmscan.c:7283 rmqueue mm/page_alloc.c:3050 [inline] get_page_from_freelist+0x9bb/0x2e50 mm/page_alloc.c:3436 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4695 alloc_pages_mpol_noprof+0x275/0x610 mm/mempolicy.c:2263 folio_alloc_mpol_noprof+0x36/0xd0 mm/mempolicy.c:2281 shmem_alloc_folio+0x135/0x160 mm/shmem.c:1722 shmem_alloc_and_add_folio+0x19c/0xce0 mm/shmem.c:1782 shmem_get_folio_gfp+0xa62/0x15e0 mm/shmem.c:2188 shmem_get_folio mm/shmem.c:2293 [inline] shmem_write_begin+0x15a/0x360 mm/shmem.c:2898 generic_perform_write+0x312/0xaa0 mm/filemap.c:4019 shmem_file_write_iter+0x114/0x140 mm/shmem.c:3074 __kernel_write_iter+0x310/0xa80 fs/read_write.c:523 dump_emit_page fs/coredump.c:893 [inline] dump_user_range+0x389/0x8a0 fs/coredump.c:954 elf_core_dump+0x27c1/0x39a0 fs/binfmt_elf.c:2116 do_coredump+0x29c5/0x3de0 fs/coredump.c:767 get_signal+0x23d4/0x2770 kernel/signal.c:2902 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [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+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&pgdat->kswapd_wait){....}-{2:2}: check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x24ed/0x3cb0 kernel/locking/lockdep.c:5142 lock_acquire kernel/locking/lockdep.c:5759 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __wake_up_common_lock kernel/sched/wait.c:105 [inline] __wake_up+0x1c/0x60 kernel/sched/wait.c:127 wakeup_kswapd+0x45e/0x640 mm/vmscan.c:7283 rmqueue mm/page_alloc.c:3050 [inline] get_page_from_freelist+0x9bb/0x2e50 mm/page_alloc.c:3436 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4695 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x4e/0xf0 mm/slub.c:2321 allocate_slab mm/slub.c:2484 [inline] new_slab+0x84/0x260 mm/slub.c:2537 ___slab_alloc+0xdac/0x1870 mm/slub.c:3723 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3813 __slab_alloc_node mm/slub.c:3866 [inline] slab_alloc_node mm/slub.c:4025 [inline] __do_kmalloc_node mm/slub.c:4157 [inline] __kmalloc_node_noprof+0x357/0x430 mm/slub.c:4164 kmalloc_node_noprof include/linux/slab.h:708 [inline] bpf_map_kmalloc_node+0x98/0x4a0 kernel/bpf/syscall.c:422 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:299 [inline] trie_update_elem+0x1ef/0xe00 kernel/bpf/lpm_trie.c:342 bpf_map_update_value+0x2c1/0x6c0 kernel/bpf/syscall.c:203 generic_map_update_batch+0x454/0x5f0 kernel/bpf/syscall.c:1889 bpf_map_do_batch+0x64a/0x720 kernel/bpf/syscall.c:5218 __sys_bpf+0x19a9/0x4a00 kernel/bpf/syscall.c:5774 __do_sys_bpf kernel/bpf/syscall.c:5817 [inline] __se_sys_bpf kernel/bpf/syscall.c:5815 [inline] __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5815 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &pgdat->kswapd_wait --> &rq->__lock --> &trie->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&trie->lock); lock(&rq->__lock); lock(&trie->lock); lock(&pgdat->kswapd_wait); *** DEADLOCK *** 2 locks held by syz.2.827/8984: #0: ffffffff8ddb5be0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff8ddb5be0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8ddb5be0 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x24b/0x6c0 kernel/bpf/syscall.c:202 #1: ffff88802f5771f8 (&trie->lock){..-.}-{2:2}, at: trie_update_elem+0xc8/0xe00 kernel/bpf/lpm_trie.c:333 stack backtrace: CPU: 0 UID: 0 PID: 8984 Comm: syz.2.827 Not tainted 6.11.0-rc5-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2186 check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x24ed/0x3cb0 kernel/locking/lockdep.c:5142 lock_acquire kernel/locking/lockdep.c:5759 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __wake_up_common_lock kernel/sched/wait.c:105 [inline] __wake_up+0x1c/0x60 kernel/sched/wait.c:127 wakeup_kswapd+0x45e/0x640 mm/vmscan.c:7283 rmqueue mm/page_alloc.c:3050 [inline] get_page_from_freelist+0x9bb/0x2e50 mm/page_alloc.c:3436 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4695 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x4e/0xf0 mm/slub.c:2321 allocate_slab mm/slub.c:2484 [inline] new_slab+0x84/0x260 mm/slub.c:2537 ___slab_alloc+0xdac/0x1870 mm/slub.c:3723 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3813 __slab_alloc_node mm/slub.c:3866 [inline] slab_alloc_node mm/slub.c:4025 [inline] __do_kmalloc_node mm/slub.c:4157 [inline] __kmalloc_node_noprof+0x357/0x430 mm/slub.c:4164 kmalloc_node_noprof include/linux/slab.h:708 [inline] bpf_map_kmalloc_node+0x98/0x4a0 kernel/bpf/syscall.c:422 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:299 [inline] trie_update_elem+0x1ef/0xe00 kernel/bpf/lpm_trie.c:342 bpf_map_update_value+0x2c1/0x6c0 kernel/bpf/syscall.c:203 generic_map_update_batch+0x454/0x5f0 kernel/bpf/syscall.c:1889 bpf_map_do_batch+0x64a/0x720 kernel/bpf/syscall.c:5218 __sys_bpf+0x19a9/0x4a00 kernel/bpf/syscall.c:5774 __do_sys_bpf kernel/bpf/syscall.c:5817 [inline] __se_sys_bpf kernel/bpf/syscall.c:5815 [inline] __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5815 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5194979e79 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:00007f5195719038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f5194b15f80 RCX: 00007f5194979e79 RDX: 0000000000000038 RSI: 0000000020000640 RDI: 000000000000001a RBP: 00007f51949e793e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5194b15f80 R15: 00007fff19243b48