============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.1.2825/20746 is trying to acquire lock: ffff88804fe04038 (rhashtable_bucket){-.-.}-{0:0}, at: rht_lock+0x8b/0x180 include/linux/rhashtable.h:330 but task is already holding lock: ffff88807d278438 (rhashtable_bucket){-.-.}-{0:0}, at: rht_lock+0x8b/0x180 include/linux/rhashtable.h:330 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 locks held by syz.1.2825/20746: 6, last CPU#0: #0: ffff88807757c180 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #0: ffff88807757c180 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x7a/0x1f0 net/socket.c:734 #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: __rhashtable_remove_fast include/linux/rhashtable.h:1136 [inline] #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rhashtable_remove_fast include/linux/rhashtable.h:1174 [inline] #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: netlink_remove net/netlink/af_netlink.c:599 [inline] #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: netlink_release+0x106/0x1a80 net/netlink/af_netlink.c:726 #2: ffff88807d278438 (rhashtable_bucket){-.-.}-{0:0}, at: rht_lock+0x8b/0x180 include/linux/rhashtable.h:330 #3: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #3: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: trace_call_bpf+0xb4/0xb80 kernel/trace/bpf_trace.c:-1 #4: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #4: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #4: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline] #4: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rhtab_map_delete_elem+0x21/0x190 kernel/bpf/hashtab.c:3007 #5: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #5: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #5: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: __rhashtable_remove_fast include/linux/rhashtable.h:1136 [inline] #5: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rhashtable_remove_fast include/linux/rhashtable.h:1174 [inline] #5: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rhtab_delete_elem+0x15f/0x1b00 kernel/bpf/hashtab.c:-1 stack backtrace: CPU: 0 UID: 0 PID: 20746 Comm: syz.1.2825 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_deadlock_bug+0x27a/0x290 kernel/locking/lockdep.c:3085 check_deadlock kernel/locking/lockdep.c:3137 [inline] validate_chain kernel/locking/lockdep.c:3939 [inline] __lock_acquire+0x25db/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 rht_lock+0xa3/0x180 include/linux/rhashtable.h:330 __rhashtable_remove_fast_one include/linux/rhashtable.h:1064 [inline] __rhashtable_remove_fast include/linux/rhashtable.h:1145 [inline] rhashtable_remove_fast include/linux/rhashtable.h:1174 [inline] rhtab_delete_elem+0x407/0x1b00 kernel/bpf/hashtab.c:2983 rhtab_map_delete_elem+0xe2/0x190 kernel/bpf/hashtab.c:3013 bpf_prog_a4f1e23443ac9f8e+0x4e/0x56 bpf_dispatcher_nop_func include/linux/bpf.h:1488 [inline] __bpf_prog_run include/linux/filter.h:779 [inline] bpf_prog_run include/linux/filter.h:786 [inline] bpf_prog_run_array include/linux/bpf.h:2641 [inline] trace_call_bpf+0x3f1/0xb80 kernel/trace/bpf_trace.c:147 perf_trace_run_bpf_submit+0x78/0x170 kernel/events/core.c:11433 do_perf_trace_lock include/trace/events/lock.h:49 [inline] perf_trace_lock+0x32e/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+0x396/0x3c0 kernel/locking/lockdep.c:5954 rht_unlock+0x26/0x140 include/linux/rhashtable.h:352 __rhashtable_remove_fast_one include/linux/rhashtable.h:1115 [inline] __rhashtable_remove_fast include/linux/rhashtable.h:1145 [inline] rhashtable_remove_fast include/linux/rhashtable.h:1174 [inline] netlink_remove net/netlink/af_netlink.c:599 [inline] netlink_release+0x5cb/0x1a80 net/netlink/af_netlink.c:726 __sock_release+0xa0/0x1f0 net/socket.c:735 sock_close+0x1c/0x30 net/socket.c:1526 __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+0x204/0x770 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:343 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f48c5f9e159 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:00007ffd7c789708 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f48c6227da0 RCX: 00007f48c5f9e159 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f48c6227da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007f48c6227cb0 R11: 0000000000000246 R12: 000000000010082c R13: 00007f48c622618c R14: 000000000010069d R15: 00007f48c6226180