====================================================== WARNING: possible circular locking dependency detected 6.1.82-syzkaller #0 Not tainted ------------------------------------------------------ syz-fuzzer/11553 is trying to acquire lock: ffff888074075a18 (&htab->buckets[i].lock ){+...}-{2:2} , at: sock_hash_delete_elem+0xac/0x2f0 net/core/sock_map.c:932 but task is already holding lock: ffff8880b982a4d8 (hrtimer_bases.lock ){-.-.}-{2:2} , at: lock_hrtimer_base kernel/time/hrtimer.c:173 [inline] , at: hrtimer_start_range_ns+0xd8/0xc50 kernel/time/hrtimer.c:1297 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 ( hrtimer_bases.lock){-.-.}-{2:2} : lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 lock_hrtimer_base kernel/time/hrtimer.c:173 [inline] hrtimer_start_range_ns+0xd8/0xc50 kernel/time/hrtimer.c:1297 hrtimer_start include/linux/hrtimer.h:420 [inline] run_page_cache_worker kernel/rcu/tree.c:3292 [inline] kvfree_call_rcu+0x72b/0x8c0 kernel/rcu/tree.c:3403 rtnl_register_internal+0x489/0x580 net/core/rtnetlink.c:260 rtnl_register+0x32/0x70 net/core/rtnetlink.c:310 ip_rt_init+0x335/0x3c7 net/ipv4/route.c:3768 ip_init+0xa/0x14 net/ipv4/ip_output.c:1767 inet_init+0x2ae/0x3c0 net/ipv4/af_inet.c:2031 do_one_initcall+0x265/0x8f0 init/main.c:1296 do_initcall_level+0x157/0x207 init/main.c:1369 do_initcalls+0x49/0x86 init/main.c:1385 kernel_init_freeable+0x45c/0x60f init/main.c:1624 kernel_init+0x19/0x290 init/main.c:1512 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307 -> #1 ( krc.lock){..-.}-{2:2} : lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:2990 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3310 [inline] kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3401 sock_hash_free_elem net/core/sock_map.c:893 [inline] sock_hash_delete_from_link net/core/sock_map.c:916 [inline] sock_map_unlink net/core/sock_map.c:1550 [inline] sock_map_remove_links+0x46f/0x550 net/core/sock_map.c:1562 sock_map_close+0x118/0x2d0 net/core/sock_map.c:1627 unix_release+0x7e/0xc0 net/unix/af_unix.c:1038 __sock_release net/socket.c:654 [inline] sock_close+0xcd/0x230 net/socket.c:1400 __fput+0x3b7/0x890 fs/file_table.c:320 task_work_run+0x246/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:297 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 ( &htab->buckets[i].lock ){+...}-{2:2} : check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178 sock_hash_delete_elem+0xac/0x2f0 net/core/sock_map.c:932 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline] __bpf_prog_run include/linux/filter.h:600 [inline] bpf_prog_run include/linux/filter.h:607 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline] bpf_trace_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2312 trace_hrtimer_start include/trace/events/timer.h:202 [inline] debug_activate kernel/time/hrtimer.c:476 [inline] enqueue_hrtimer+0x382/0x410 kernel/time/hrtimer.c:1084 __hrtimer_start_range_ns kernel/time/hrtimer.c:1259 [inline] hrtimer_start_range_ns+0xa9c/0xc50 kernel/time/hrtimer.c:1299 hrtimer_start_expires include/linux/hrtimer.h:434 [inline] hrtimer_sleeper_start_expires kernel/time/hrtimer.c:1966 [inline] schedule_hrtimeout_range_clock+0x272/0x480 kernel/time/hrtimer.c:2305 ep_poll fs/eventpoll.c:1884 [inline] do_epoll_wait+0x1be9/0x1e60 fs/eventpoll.c:2262 do_epoll_pwait+0x56/0x1d0 fs/eventpoll.c:2296 __do_sys_epoll_pwait fs/eventpoll.c:2309 [inline] __se_sys_epoll_pwait fs/eventpoll.c:2303 [inline] __x64_sys_epoll_pwait+0x2b4/0x300 fs/eventpoll.c:2303 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: &htab->buckets[i].lock --> krc.lock --> hrtimer_bases.lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(hrtimer_bases.lock ); lock( krc.lock); lock(hrtimer_bases.lock ); lock( &htab->buckets[i].lock); *** DEADLOCK *** 2 locks held by syz-fuzzer/11553: #0: ffff8880b982a4d8 (hrtimer_bases.lock ){-.-.}-{2:2} , at: lock_hrtimer_base kernel/time/hrtimer.c:173 [inline] , at: hrtimer_start_range_ns+0xd8/0xc50 kernel/time/hrtimer.c:1297 #1: ffffffff8d12a940 (rcu_read_lock ){....}-{1:2} , at: rcu_lock_acquire include/linux/rcupdate.h:319 [inline] , at: rcu_read_lock include/linux/rcupdate.h:760 [inline] , at: __bpf_trace_run kernel/trace/bpf_trace.c:2272 [inline] , at: bpf_trace_run2+0x110/0x410 kernel/trace/bpf_trace.c:2312 stack backtrace: CPU: 0 PID: 11553 Comm: syz-fuzzer Not tainted 6.1.82-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178 sock_hash_delete_elem+0xac/0x2f0 net/core/sock_map.c:932 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline] __bpf_prog_run include/linux/filter.h:600 [inline] bpf_prog_run include/linux/filter.h:607 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline] bpf_trace_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2312 trace_hrtimer_start include/trace/events/timer.h:202 [inline] debug_activate kernel/time/hrtimer.c:476 [inline] enqueue_hrtimer+0x382/0x410 kernel/time/hrtimer.c:1084 __hrtimer_start_range_ns kernel/time/hrtimer.c:1259 [inline] hrtimer_start_range_ns+0xa9c/0xc50 kernel/time/hrtimer.c:1299 hrtimer_start_expires include/linux/hrtimer.h:434 [inline] hrtimer_sleeper_start_expires kernel/time/hrtimer.c:1966 [inline] schedule_hrtimeout_range_clock+0x272/0x480 kernel/time/hrtimer.c:2305 ep_poll fs/eventpoll.c:1884 [inline] do_epoll_wait+0x1be9/0x1e60 fs/eventpoll.c:2262 do_epoll_pwait+0x56/0x1d0 fs/eventpoll.c:2296 __do_sys_epoll_pwait fs/eventpoll.c:2309 [inline] __se_sys_epoll_pwait fs/eventpoll.c:2303 [inline] __x64_sys_epoll_pwait+0x2b4/0x300 fs/eventpoll.c:2303 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x40720e Code: 48 83 ec 38 e8 13 00 00 00 48 83 c4 38 5d c3 cc cc cc cc cc cc cc cc cc cc cc cc cc 49 89 f2 48 89 fa 48 89 ce 48 89 df 0f 05 <48> 3d 01 f0 ff ff 76 15 48 f7 d8 48 89 c1 48 c7 c0 ff ff ff ff 48 RSP: 002b:000000c00b3ab748 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000040720e RDX: 0000000000000080 RSI: 000000c00b3ab818 RDI: 0000000000000004 RBP: 000000c00b3ab790 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000004b R11: 0000000000000246 R12: 000000c00b3ab820 R13: 000000c013f3b95c R14: 000000c00addf1e0 R15: 0000000000000000