============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.1.5234/31873 is trying to acquire lock: ffff88802b346038 (rhashtable_bucket){-.-.}-{0:0}, at: rht_lock+0x8b/0x180 include/linux/rhashtable.h:331 but task is already holding lock: ffff88803285e838 (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.1.5234/31873: #0: ffff88807d6ce260 (sk_lock-AF_NETLINK){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff88807d6ce260 (sk_lock-AF_NETLINK){+.+.}-{0:0}, at: netlink_insert+0xcb/0x1360 net/netlink/af_netlink.c:558 #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_insert_fast include/linux/rhashtable.h:774 [inline] #1: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rhashtable_lookup_insert_key include/linux/rhashtable.h:1020 [inline] #1: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: __netlink_insert net/netlink/af_netlink.c:508 [inline] #1: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: netlink_insert+0x2b3/0x1360 net/netlink/af_netlink.c:569 #2: ffff88803285e838 (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: 1 UID: 0 PID: 31873 Comm: syz.1.5234 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_insert_fast include/linux/rhashtable.h:850 [inline] rhashtable_lookup_insert_key include/linux/rhashtable.h:1020 [inline] __netlink_insert net/netlink/af_netlink.c:508 [inline] netlink_insert+0xa4a/0x1360 net/netlink/af_netlink.c:569 netlink_autobind+0x22d/0x300 net/netlink/af_netlink.c:827 netlink_sendmsg+0x531/0xb40 net/netlink/af_netlink.c:1863 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775 __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2684 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738 __sys_sendmsg net/socket.c:2770 [inline] __do_sys_sendmsg net/socket.c:2775 [inline] __se_sys_sendmsg net/socket.c:2773 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f31c239de99 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:00007f31c3213028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f31c2625fa0 RCX: 00007f31c239de99 RDX: 0000000000008000 RSI: 0000200000000180 RDI: 0000000000000006 RBP: 00007f31c2433eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f31c2626038 R14: 00007f31c2625fa0 R15: 00007ffdd1faf868 netlink: 253 bytes leftover after parsing attributes in process `syz.1.5234'. netlink: 'syz.1.5234': attribute type 1 has an invalid length. netlink: 14452 bytes leftover after parsing attributes in process `syz.1.5234'.