============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.2.442/7554 is trying to acquire lock: ffff88802e065038 (rhashtable_bucket){-.-.}-{0:0}, at: rht_lock+0x8b/0x180 include/linux/rhashtable.h:331 but task is already holding lock: ffff8880774bbe38 (rhashtable_bucket){-.-.}-{0:0}, at: rht_lock+0x8b/0x180 include/linux/rhashtable.h:331 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(rhashtable_bucket); lock(rhashtable_bucket); *** DEADLOCK *** May be due to missing lock nesting notation 6 locks held by syz.2.442/7554: #0: ffff888076959940 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #0: ffff888076959940 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:709 [inline] #0: ffff888076959940 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x82/0x220 net/socket.c:1501 #1: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: __rhashtable_remove_fast include/linux/rhashtable.h:1137 [inline] #1: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rhashtable_remove_fast include/linux/rhashtable.h:1175 [inline] #1: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: netlink_remove net/netlink/af_netlink.c:599 [inline] #1: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: netlink_release+0x106/0x1a80 net/netlink/af_netlink.c:726 #2: ffff8880774bbe38 (rhashtable_bucket){-.-.}-{0:0}, at: rht_lock+0x8b/0x180 include/linux/rhashtable.h:331 #3: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #3: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: trace_call_bpf+0xb6/0xb80 kernel/trace/bpf_trace.c:-1 #4: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #4: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #4: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1183 [inline] #4: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rhtab_map_delete_elem+0x21/0x190 kernel/bpf/hashtab.c:2979 #5: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #5: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #5: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: __rhashtable_remove_fast include/linux/rhashtable.h:1137 [inline] #5: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rhashtable_remove_fast include/linux/rhashtable.h:1175 [inline] #5: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rhtab_delete_elem+0x15c/0x1b30 kernel/bpf/hashtab.c:-1 stack backtrace: CPU: 0 UID: 0 PID: 7554 Comm: syz.2.442 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain kernel/locking/lockdep.c:3895 [inline] __lock_acquire+0x24df/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 rht_lock+0xa3/0x180 include/linux/rhashtable.h:331 __rhashtable_remove_fast_one include/linux/rhashtable.h:1065 [inline] __rhashtable_remove_fast include/linux/rhashtable.h:1146 [inline] rhashtable_remove_fast include/linux/rhashtable.h:1175 [inline] rhtab_delete_elem+0x404/0x1b30 kernel/bpf/hashtab.c:2954 rhtab_map_delete_elem+0xe2/0x190 kernel/bpf/hashtab.c:2985 bpf_prog_a4f1e23443ac9f8e+0x4e/0x56 bpf_dispatcher_nop_func include/linux/bpf.h:1453 [inline] __bpf_prog_run include/linux/filter.h:724 [inline] bpf_prog_run include/linux/filter.h:731 [inline] bpf_prog_run_array include/linux/bpf.h:2605 [inline] trace_call_bpf+0x3f0/0xb80 kernel/trace/bpf_trace.c:147 perf_trace_run_bpf_submit+0x78/0x170 kernel/events/core.c:11398 do_perf_trace_lock include/trace/events/lock.h:49 [inline] perf_trace_lock+0x32d/0x410 include/trace/events/lock.h:49 __do_trace_lock_release include/trace/events/lock.h:68 [inline] trace_lock_release include/trace/events/lock.h:68 [inline] lock_release+0x38e/0x3c0 kernel/locking/lockdep.c:5879 rht_assign_unlock include/linux/rhashtable.h:431 [inline] __rhashtable_remove_fast_one include/linux/rhashtable.h:1111 [inline] __rhashtable_remove_fast include/linux/rhashtable.h:1146 [inline] rhashtable_remove_fast include/linux/rhashtable.h:1175 [inline] netlink_remove net/netlink/af_netlink.c:599 [inline] netlink_release+0x8ec/0x1a80 net/netlink/af_netlink.c:726 __sock_release net/socket.c:710 [inline] sock_close+0xad/0x220 net/socket.c:1501 __fput+0x418/0xa50 fs/file_table.c:512 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4059f9de99 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff840e6e88 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f405a227da0 RCX: 00007f4059f9de99 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f405a227da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007f405a227cb0 R11: 0000000000000246 R12: 000000000002cdda R13: 00007f405a22609c R14: 000000000002cbe0 R15: 00007f405a226090