====================================================== WARNING: possible circular locking dependency detected 5.15.173-syzkaller #0 Not tainted ------------------------------------------------------ syz.2.53/5542 is trying to acquire lock: ffff888078d25c20 (&htab->lockdep_key#27){....}-{2:2}, at: htab_lock_bucket kernel/bpf/hashtab.c:183 [inline] ffff888078d25c20 (&htab->lockdep_key#27){....}-{2:2}, at: htab_map_delete_elem+0x1bd/0x560 kernel/bpf/hashtab.c:1361 but task is already holding lock: ffff88805d98a0a0 (&htab->lockdep_key#28){....}-{2:2}, at: htab_lock_bucket kernel/bpf/hashtab.c:183 [inline] ffff88805d98a0a0 (&htab->lockdep_key#28){....}-{2:2}, at: htab_map_update_elem+0x245/0x9c0 kernel/bpf/hashtab.c:1082 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&htab->lockdep_key#28){....}-{2:2}: 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 htab_lock_bucket kernel/bpf/hashtab.c:183 [inline] htab_map_delete_elem+0x1bd/0x560 kernel/bpf/hashtab.c:1361 bpf_prog_2c29ac5cdc6b1842+0x3a/0x934 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:1878 [inline] bpf_trace_run4+0x1ea/0x390 kernel/trace/bpf_trace.c:1917 __bpf_trace_mm_page_alloc+0xba/0xe0 include/trace/events/kmem.h:201 __traceiter_mm_page_alloc+0x35/0x50 include/trace/events/kmem.h:201 trace_mm_page_alloc include/trace/events/kmem.h:201 [inline] __alloc_pages+0x6e0/0x700 mm/page_alloc.c:5486 __alloc_pages_node include/linux/gfp.h:570 [inline] alloc_pages_node include/linux/gfp.h:584 [inline] kmalloc_large_node+0x7c/0x180 mm/slub.c:4421 __kmalloc_node+0x22d/0x390 mm/slub.c:4437 kmalloc_node include/linux/slab.h:614 [inline] bpf_map_kmalloc_node+0xdb/0x160 kernel/bpf/syscall.c:430 alloc_htab_elem+0x28b/0x920 kernel/bpf/hashtab.c:973 htab_map_update_elem+0x3cb/0x9c0 kernel/bpf/hashtab.c:1106 bpf_map_update_value+0x5d7/0x6c0 kernel/bpf/syscall.c:221 map_update_elem+0x6a0/0x7c0 kernel/bpf/syscall.c:1185 __sys_bpf+0x2fd/0x670 kernel/bpf/syscall.c:4639 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline] __se_sys_bpf kernel/bpf/syscall.c:4753 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753 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 -> #0 (&htab->lockdep_key#27){....}-{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 htab_lock_bucket kernel/bpf/hashtab.c:183 [inline] htab_map_delete_elem+0x1bd/0x560 kernel/bpf/hashtab.c:1361 bpf_prog_2c29ac5cdc6b1842+0x3a/0xb78 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:1878 [inline] bpf_trace_run4+0x1ea/0x390 kernel/trace/bpf_trace.c:1917 __bpf_trace_mm_page_alloc+0xba/0xe0 include/trace/events/kmem.h:201 __traceiter_mm_page_alloc+0x35/0x50 include/trace/events/kmem.h:201 trace_mm_page_alloc include/trace/events/kmem.h:201 [inline] __alloc_pages+0x6e0/0x700 mm/page_alloc.c:5486 __alloc_pages_node include/linux/gfp.h:570 [inline] alloc_pages_node include/linux/gfp.h:584 [inline] kmalloc_large_node+0x7c/0x180 mm/slub.c:4421 __kmalloc_node+0x22d/0x390 mm/slub.c:4437 kmalloc_node include/linux/slab.h:614 [inline] bpf_map_kmalloc_node+0xdb/0x160 kernel/bpf/syscall.c:430 alloc_htab_elem+0x28b/0x920 kernel/bpf/hashtab.c:973 htab_map_update_elem+0x3cb/0x9c0 kernel/bpf/hashtab.c:1106 bpf_map_update_value+0x5d7/0x6c0 kernel/bpf/syscall.c:221 map_update_elem+0x6a0/0x7c0 kernel/bpf/syscall.c:1185 __sys_bpf+0x2fd/0x670 kernel/bpf/syscall.c:4639 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline] __se_sys_bpf kernel/bpf/syscall.c:4753 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753 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: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&htab->lockdep_key#28); lock(&htab->lockdep_key#27); lock(&htab->lockdep_key#28); lock(&htab->lockdep_key#27); *** DEADLOCK *** 3 locks held by syz.2.53/5542: #0: ffffffff8c91fc60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 #1: ffff88805d98a0a0 (&htab->lockdep_key#28){....}-{2:2}, at: htab_lock_bucket kernel/bpf/hashtab.c:183 [inline] #1: ffff88805d98a0a0 (&htab->lockdep_key#28){....}-{2:2}, at: htab_map_update_elem+0x245/0x9c0 kernel/bpf/hashtab.c:1082 #2: ffffffff8c91fc60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 stack backtrace: CPU: 0 PID: 5542 Comm: syz.2.53 Not tainted 5.15.173-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 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 htab_lock_bucket kernel/bpf/hashtab.c:183 [inline] htab_map_delete_elem+0x1bd/0x560 kernel/bpf/hashtab.c:1361 bpf_prog_2c29ac5cdc6b1842+0x3a/0xb78 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:1878 [inline] bpf_trace_run4+0x1ea/0x390 kernel/trace/bpf_trace.c:1917 __bpf_trace_mm_page_alloc+0xba/0xe0 include/trace/events/kmem.h:201 __traceiter_mm_page_alloc+0x35/0x50 include/trace/events/kmem.h:201 trace_mm_page_alloc include/trace/events/kmem.h:201 [inline] __alloc_pages+0x6e0/0x700 mm/page_alloc.c:5486 __alloc_pages_node include/linux/gfp.h:570 [inline] alloc_pages_node include/linux/gfp.h:584 [inline] kmalloc_large_node+0x7c/0x180 mm/slub.c:4421 __kmalloc_node+0x22d/0x390 mm/slub.c:4437 kmalloc_node include/linux/slab.h:614 [inline] bpf_map_kmalloc_node+0xdb/0x160 kernel/bpf/syscall.c:430 alloc_htab_elem+0x28b/0x920 kernel/bpf/hashtab.c:973 htab_map_update_elem+0x3cb/0x9c0 kernel/bpf/hashtab.c:1106 bpf_map_update_value+0x5d7/0x6c0 kernel/bpf/syscall.c:221 map_update_elem+0x6a0/0x7c0 kernel/bpf/syscall.c:1185 __sys_bpf+0x2fd/0x670 kernel/bpf/syscall.c:4639 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline] __se_sys_bpf kernel/bpf/syscall.c:4753 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753 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: 0033:0x7fb7de52c819 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:00007fb7dd7ac038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fb7de6e3fa0 RCX: 00007fb7de52c819 RDX: 0000000000000020 RSI: 0000000020000280 RDI: 0000000000000002 RBP: 00007fb7de59f75e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb7de6e3fa0 R15: 00007ffe6a299cd8