====================================================== WARNING: possible circular locking dependency detected 6.1.16-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.2/8836 is trying to acquire lock: ffff88801edee490 (&q->queue_lock){..-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:375 [inline] ffff88801edee490 (&q->queue_lock){..-.}-{2:2}, at: throtl_pending_timer_fn+0x10d/0x1be0 block/blk-throttle.c:1193 but task is already holding lock: ffffc900001e0bc0 ((&sq->pending_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline] ffffc900001e0bc0 ((&sq->pending_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbd/0x840 kernel/time/timer.c:1464 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 ((&sq->pending_timer)){+.-.}-{0:0}: lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669 del_timer_sync+0x111/0x2e0 kernel/time/timer.c:1417 throtl_pd_free+0x15/0x40 block/blk-throttle.c:493 blkcg_deactivate_policy+0x32d/0x550 block/blk-cgroup.c:1499 blk_throtl_exit+0xa6/0x140 block/blk-throttle.c:2406 disk_release+0x1dd/0x380 block/genhd.c:1171 device_release+0x91/0x1c0 kobject_cleanup lib/kobject.c:681 [inline] kobject_release lib/kobject.c:712 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x224/0x460 lib/kobject.c:729 do_floppy_init+0x373/0xc59 drivers/block/floppy.c:4758 async_run_entry_fn+0xa2/0x410 kernel/async.c:127 process_one_work+0x909/0x1380 kernel/workqueue.c:2289 worker_thread+0xa5f/0x1210 kernel/workqueue.c:2436 kthread+0x268/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 -> #1 (&blkcg->lock){....}-{2:2}: lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:350 [inline] blkg_create+0xa94/0x1280 block/blk-cgroup.c:336 blkcg_init_disk+0xee/0x350 block/blk-cgroup.c:1260 __alloc_disk_node+0x2ce/0x590 block/genhd.c:1385 __blk_mq_alloc_disk+0x11e/0x1e0 block/blk-mq.c:4081 floppy_alloc_disk+0x54/0x360 drivers/block/floppy.c:4514 do_floppy_init+0x1af/0xc59 drivers/block/floppy.c:4595 async_run_entry_fn+0xa2/0x410 kernel/async.c:127 process_one_work+0x909/0x1380 kernel/workqueue.c:2289 worker_thread+0xa5f/0x1210 kernel/workqueue.c:2436 kthread+0x268/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 -> #0 (&q->queue_lock){..-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056 lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0xcf/0x110 kernel/locking/spinlock.c:170 spin_lock_irq include/linux/spinlock.h:375 [inline] throtl_pending_timer_fn+0x10d/0x1be0 block/blk-throttle.c:1193 call_timer_fn+0x200/0x840 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1790 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803 __do_softirq+0x30d/0xb1b kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x155/0x240 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194 rcu_preempt_deferred_qs_irqrestore+0x873/0xc50 rcu_read_unlock_special+0x467/0x540 kernel/rcu/tree_plugin.h:679 __rcu_read_unlock+0x92/0x100 kernel/rcu/tree_plugin.h:424 rcu_read_unlock include/linux/rcupdate.h:779 [inline] page_ext_put+0x91/0xa0 mm/page_ext.c:182 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x3573/0x3700 mm/page_alloc.c:4291 __alloc_pages+0x28d/0x7e0 mm/page_alloc.c:5558 __alloc_pages_node include/linux/gfp.h:237 [inline] alloc_pages_node include/linux/gfp.h:260 [inline] __kmalloc_large_node+0x91/0x1d0 mm/slab_common.c:1096 __do_kmalloc_node mm/slab_common.c:943 [inline] __kmalloc_node_track_caller+0xf3/0x190 mm/slab_common.c:975 kmalloc_reserve net/core/skbuff.c:437 [inline] __alloc_skb+0x126/0x620 net/core/skbuff.c:509 alloc_skb_fclone include/linux/skbuff.h:1317 [inline] tipc_buf_acquire net/tipc/msg.c:72 [inline] tipc_msg_build+0x149/0x1230 net/tipc/msg.c:386 __tipc_sendstream+0xa39/0x1610 net/tipc/socket.c:1619 tipc_sendstream+0x51/0x70 net/tipc/socket.c:1550 sock_sendmsg_nosec net/socket.c:716 [inline] sock_sendmsg net/socket.c:736 [inline] sock_write_iter+0x394/0x4e0 net/socket.c:1113 call_write_iter include/linux/fs.h:2205 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x7ae/0xba0 fs/read_write.c:584 ksys_write+0x19c/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: &q->queue_lock --> &blkcg->lock --> (&sq->pending_timer) Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((&sq->pending_timer)); lock(&blkcg->lock); lock((&sq->pending_timer)); lock(&q->queue_lock); *** DEADLOCK *** 3 locks held by syz-executor.2/8836: #0: ffff88804fb0a9b0 (sk_lock-AF_TIPC){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1721 [inline] #0: ffff88804fb0a9b0 (sk_lock-AF_TIPC){+.+.}-{0:0}, at: __tipc_sendstream+0x70f/0x1610 net/tipc/socket.c:1586 #1: ffffffff8cf272a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:305 #2: ffffc900001e0bc0 ((&sq->pending_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline] #2: ffffc900001e0bc0 ((&sq->pending_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbd/0x840 kernel/time/timer.c:1464 stack backtrace: CPU: 1 PID: 8836 Comm: syz-executor.2 Not tainted 6.1.16-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 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:2178 check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056 lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0xcf/0x110 kernel/locking/spinlock.c:170 spin_lock_irq include/linux/spinlock.h:375 [inline] throtl_pending_timer_fn+0x10d/0x1be0 block/blk-throttle.c:1193 call_timer_fn+0x200/0x840 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1790 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803 __do_softirq+0x30d/0xb1b kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x155/0x240 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 f2 45 4d f7 f6 44 24 21 02 75 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 d7 df ca f6 65 8b 05 18 f0 6e 75 85 c0 74 3f 48 c7 04 24 0e 36 RSP: 0018:ffffc9000b3c6f80 EFLAGS: 00000206 RAX: 969394355a27d400 RBX: 1ffff92001678df4 RCX: ffffffff816aaefa RDX: dffffc0000000000 RSI: ffffffff8aebd320 RDI: 0000000000000001 RBP: ffffc9000b3c7010 R08: dffffc0000000000 R09: fffffbfff204cc56 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 1ffff92001678df0 R14: ffffc9000b3c6fa0 R15: 0000000000000246 rcu_preempt_deferred_qs_irqrestore+0x873/0xc50 rcu_read_unlock_special+0x467/0x540 kernel/rcu/tree_plugin.h:679 __rcu_read_unlock+0x92/0x100 kernel/rcu/tree_plugin.h:424 rcu_read_unlock include/linux/rcupdate.h:779 [inline] page_ext_put+0x91/0xa0 mm/page_ext.c:182 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x3573/0x3700 mm/page_alloc.c:4291 __alloc_pages+0x28d/0x7e0 mm/page_alloc.c:5558 __alloc_pages_node include/linux/gfp.h:237 [inline] alloc_pages_node include/linux/gfp.h:260 [inline] __kmalloc_large_node+0x91/0x1d0 mm/slab_common.c:1096 __do_kmalloc_node mm/slab_common.c:943 [inline] __kmalloc_node_track_caller+0xf3/0x190 mm/slab_common.c:975 kmalloc_reserve net/core/skbuff.c:437 [inline] __alloc_skb+0x126/0x620 net/core/skbuff.c:509 alloc_skb_fclone include/linux/skbuff.h:1317 [inline] tipc_buf_acquire net/tipc/msg.c:72 [inline] tipc_msg_build+0x149/0x1230 net/tipc/msg.c:386 __tipc_sendstream+0xa39/0x1610 net/tipc/socket.c:1619 tipc_sendstream+0x51/0x70 net/tipc/socket.c:1550 sock_sendmsg_nosec net/socket.c:716 [inline] sock_sendmsg net/socket.c:736 [inline] sock_write_iter+0x394/0x4e0 net/socket.c:1113 call_write_iter include/linux/fs.h:2205 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x7ae/0xba0 fs/read_write.c:584 ksys_write+0x19c/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7ff79508c0f9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff795d37168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ff7951ac120 RCX: 00007ff79508c0f9 RDX: 000000002000011a RSI: 0000000020000080 RDI: 0000000000000005 RBP: 00007ff7950e7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd29f6aeff R14: 00007ff795d37300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 9c pushfq 1: 8f 44 24 20 popq 0x20(%rsp) 5: 42 80 3c 23 00 cmpb $0x0,(%rbx,%r12,1) a: 74 08 je 0x14 c: 4c 89 f7 mov %r14,%rdi f: e8 f2 45 4d f7 callq 0xf74d4606 14: f6 44 24 21 02 testb $0x2,0x21(%rsp) 19: 75 4e jne 0x69 1b: 41 f7 c7 00 02 00 00 test $0x200,%r15d 22: 74 01 je 0x25 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 d7 df ca f6 callq 0xf6cae006 <-- trapping instruction 2f: 65 8b 05 18 f0 6e 75 mov %gs:0x756ef018(%rip),%eax # 0x756ef04e 36: 85 c0 test %eax,%eax 38: 74 3f je 0x79 3a: 48 rex.W 3b: c7 .byte 0xc7 3c: 04 24 add $0x24,%al 3e: 0e (bad) 3f: 36 ss