====================================================== WARNING: possible circular locking dependency detected 6.11.0-rc7-syzkaller #0 Not tainted ------------------------------------------------------ syz.0.2503/13148 is trying to acquire lock: ffff88803fffece0 (&pgdat->kswapd_wait){..-.}-{2:2}, at: __wake_up_common_lock kernel/sched/wait.c:105 [inline] ffff88803fffece0 (&pgdat->kswapd_wait){..-.}-{2:2}, at: __wake_up+0x1c/0x60 kernel/sched/wait.c:127 but task is already holding lock: ffff8880606021f8 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc7/0xdb0 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 0xffffffffa0001fea bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2406 [inline] bpf_trace_run4+0x245/0x5a0 kernel/trace/bpf_trace.c:2449 __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_time32 kernel/futex/syscalls.c:509 [inline] __se_sys_futex_time32 kernel/futex/syscalls.c:492 [inline] __ia32_sys_futex_time32+0x1da/0x460 kernel/futex/syscalls.c:492 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #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+0x4710/0x6f50 kernel/fork.c:2483 kernel_clone+0xfd/0x960 kernel/fork.c:2781 user_mode_thread+0xb4/0xf0 kernel/fork.c:2859 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:7263 rmqueue mm/page_alloc.c:3057 [inline] get_page_from_freelist+0x9bb/0x2e50 mm/page_alloc.c:3443 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4702 __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:2325 allocate_slab mm/slub.c:2488 [inline] new_slab+0x84/0x260 mm/slub.c:2541 ___slab_alloc+0xdac/0x1870 mm/slub.c:3727 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3817 __slab_alloc_node mm/slub.c:3870 [inline] slab_alloc_node mm/slub.c:4029 [inline] kmem_cache_alloc_noprof+0x2ae/0x2f0 mm/slub.c:4048 radix_tree_node_alloc.constprop.0+0x1e8/0x350 lib/radix-tree.c:253 idr_get_free+0x528/0xa40 lib/radix-tree.c:1506 idr_alloc_u32+0x191/0x2f0 lib/idr.c:46 idr_alloc_cyclic+0x10c/0x230 lib/idr.c:125 __kernfs_new_node+0x11b/0x890 fs/kernfs/dir.c:630 kernfs_new_node+0x186/0x240 fs/kernfs/dir.c:700 kernfs_create_dir_ns+0x4c/0x150 fs/kernfs/dir.c:1061 internal_create_group+0x34b/0xe50 fs/sysfs/group.c:167 kernel_add_sysfs_param kernel/params.c:819 [inline] param_sysfs_builtin kernel/params.c:856 [inline] param_sysfs_builtin_init+0x28e/0x3c0 kernel/params.c:990 do_one_initcall+0x128/0x630 init/main.c:1267 do_initcall_level init/main.c:1329 [inline] do_initcalls init/main.c:1345 [inline] do_basic_setup init/main.c:1364 [inline] kernel_init_freeable+0x660/0xc50 init/main.c:1578 kernel_init+0x1c/0x2b0 init/main.c:1467 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #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:7263 rmqueue mm/page_alloc.c:3057 [inline] get_page_from_freelist+0x9bb/0x2e50 mm/page_alloc.c:3443 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4702 __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:2325 allocate_slab mm/slub.c:2488 [inline] new_slab+0x84/0x260 mm/slub.c:2541 ___slab_alloc+0xdac/0x1870 mm/slub.c:3727 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3817 __slab_alloc_node mm/slub.c:3870 [inline] slab_alloc_node mm/slub.c:4029 [inline] __do_kmalloc_node mm/slub.c:4161 [inline] __kmalloc_node_noprof+0x367/0x440 mm/slub.c:4168 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/0xdb0 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+0x615/0x6e0 kernel/bpf/syscall.c:5218 __sys_bpf+0x151b/0x55e0 kernel/bpf/syscall.c:5774 __do_sys_bpf kernel/bpf/syscall.c:5817 [inline] __se_sys_bpf kernel/bpf/syscall.c:5815 [inline] __ia32_sys_bpf+0x76/0xe0 kernel/bpf/syscall.c:5815 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e 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.0.2503/13148: #0: ffffffff8ddb94a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff8ddb94a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8ddb94a0 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x24b/0x6c0 kernel/bpf/syscall.c:202 #1: ffff8880606021f8 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc7/0xdb0 kernel/bpf/lpm_trie.c:333 stack backtrace: CPU: 3 UID: 0 PID: 13148 Comm: syz.0.2503 Not tainted 6.11.0-rc7-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:7263 rmqueue mm/page_alloc.c:3057 [inline] get_page_from_freelist+0x9bb/0x2e50 mm/page_alloc.c:3443 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4702 __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:2325 allocate_slab mm/slub.c:2488 [inline] new_slab+0x84/0x260 mm/slub.c:2541 ___slab_alloc+0xdac/0x1870 mm/slub.c:3727 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3817 __slab_alloc_node mm/slub.c:3870 [inline] slab_alloc_node mm/slub.c:4029 [inline] __do_kmalloc_node mm/slub.c:4161 [inline] __kmalloc_node_noprof+0x367/0x440 mm/slub.c:4168 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/0xdb0 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+0x615/0x6e0 kernel/bpf/syscall.c:5218 __sys_bpf+0x151b/0x55e0 kernel/bpf/syscall.c:5774 __do_sys_bpf kernel/bpf/syscall.c:5817 [inline] __se_sys_bpf kernel/bpf/syscall.c:5815 [inline] __ia32_sys_bpf+0x76/0xe0 kernel/bpf/syscall.c:5815 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf73ae579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f56a656c EFLAGS: 00000296 ORIG_RAX: 0000000000000165 RAX: ffffffffffffffda RBX: 000000000000001a RCX: 0000000020000000 RDX: 0000000000000038 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi