Re: [syzbot] [kernel?] possible deadlock in __hrtimer_run_queues (2)

Hillf Danton
2024-03-26T10:32:20Z

On Sun, 24 Mar 2024 14:06:24 -0700
> syzbot found the following issue on:
>
> HEAD commit: fe46a7dd189e Merge tag 'sound-6.9-rc1' of git://git.kernel..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=17b8bbb9180000
> kernel config: https://syzkaller.appspot.com/x/.config?x=fe78468a74fdc3b7
> dashboard link: https://syzkaller.appspot.com/bug?extid=bacb240dbeebb88518ae
> compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/0f7abe4afac7/disk-fe46a7dd.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/82598d09246c/vmlinux-fe46a7dd.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/efa23788c875/bzImage-fe46a7dd.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+bacb240dbeebb88518ae@syzkaller.appspotmail.com
>
> ------------[ cut here ]------------
> ======================================================
> WARNING: possible circular locking dependency detected
> 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted
> ------------------------------------------------------
> kswapd0/88 is trying to acquire lock:
> ffffffff8e126300 (console_owner){-...}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:1997 [inline]
> ffffffff8e126300 (console_owner){-...}-{0:0}, at: vprintk_emit+0x3d6/0x770 kernel/printk/printk.c:2341
>
> but task is already holding lock:
> ffff8880b952c8d8 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1696 [inline]
> ffff8880b952c8d8 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x65a/0xd00 kernel/time/hrtimer.c:1756
>
> which lock already depends on the new lock.
>
>
> the existing dependency chain (in reverse order) is:
>
> -> #3 (hrtimer_bases.lock){-.-.}-{2:2}:
> lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
> __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
> _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
> lock_hrtimer_base kernel/time/hrtimer.c:175 [inline]
> hrtimer_start_range_ns+0xdf/0xc60 kernel/time/hrtimer.c:1303
> rpm_suspend+0x12c2/0x1780 drivers/base/power/runtime.c:606
> __pm_runtime_idle+0x131/0x1a0 drivers/base/power/runtime.c:1104
> pm_runtime_put include/linux/pm_runtime.h:448 [inline]
> __device_attach+0x3e5/0x520 drivers/base/dd.c:1048
> bus_probe_device+0x189/0x260 drivers/base/bus.c:532
> device_add+0x8ff/0xca0 drivers/base/core.c:3639
> serdev_controller_add+0x83/0x660 drivers/tty/serdev/core.c:782
> serdev_tty_port_register+0x163/0x260 drivers/tty/serdev/serdev-ttyport.c:302
> tty_port_register_device_attr_serdev+0xe1/0x160 drivers/tty/tty_port.c:191
> serial_core_add_one_port drivers/tty/serial/serial_core.c:3191 [inline]
> serial_core_register_port+0xee0/0x1e30 drivers/tty/serial/serial_core.c:3398
> serial8250_register_8250_port+0x1433/0x1cd0 drivers/tty/serial/8250/8250_core.c:1138
> serial_pnp_probe+0x7d5/0xa20 drivers/tty/serial/8250/8250_pnp.c:478
> pnp_device_probe+0x2bc/0x460 drivers/pnp/driver.c:111
> really_probe+0x2a0/0xc50 drivers/base/dd.c:658
> __driver_probe_device+0x1a2/0x3e0 drivers/base/dd.c:800
> driver_probe_device+0x50/0x430 drivers/base/dd.c:830
> __driver_attach+0x45f/0x710 drivers/base/dd.c:1216
> bus_for_each_dev+0x23b/0x2b0 drivers/base/bus.c:368
> bus_add_driver+0x347/0x620 drivers/base/bus.c:673
> driver_register+0x23a/0x320 drivers/base/driver.c:246
> serial8250_init+0x9e/0x170 drivers/tty/serial/8250/8250_core.c:1239
> do_one_initcall+0x23a/0x830 init/main.c:1241
> do_initcall_level+0x157/0x210 init/main.c:1303
> do_initcalls+0x3f/0x80 init/main.c:1319
> kernel_init_freeable+0x435/0x5d0 init/main.c:1550
> kernel_init+0x1d/0x2a0 init/main.c:1439
> ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
>
> -> #2 (&dev->power.lock){-...}-{2:2}:
> lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
> __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
> _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
> __pm_runtime_resume+0x112/0x180 drivers/base/power/runtime.c:1171
> pm_runtime_get include/linux/pm_runtime.h:396 [inline]
> __uart_start+0x17a/0x3c0 drivers/tty/serial/serial_core.c:148
> uart_write+0x427/0x5c0 drivers/tty/serial/serial_core.c:615
> process_output_block drivers/tty/n_tty.c:574 [inline]
> n_tty_write+0xd6c/0x1230 drivers/tty/n_tty.c:2379
> iterate_tty_write drivers/tty/tty_io.c:1021 [inline]
> file_tty_write+0x551/0x9b0 drivers/tty/tty_io.c:1096
> call_write_iter include/linux/fs.h:2108 [inline]
> new_sync_write fs/read_write.c:497 [inline]
> vfs_write+0xa86/0xcb0 fs/read_write.c:590
> ksys_write+0x1a0/0x2c0 fs/read_write.c:643
> do_syscall_64+0xfd/0x240
> entry_SYSCALL_64_after_hwframe+0x6d/0x75
>
> -> #1 (&port_lock_key){-.-.}-{2:2}:
> lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
> __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
> _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
> uart_port_lock_irqsave include/linux/serial_core.h:616 [inline]
> serial8250_console_write+0x1a8/0x1840 drivers/tty/serial/8250/8250_port.c:3403
> console_emit_next_record kernel/printk/printk.c:2907 [inline]
> console_flush_all+0x867/0xfd0 kernel/printk/printk.c:2973
> console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3042
> vprintk_emit+0x5a6/0x770 kernel/printk/printk.c:2342
> _printk+0xd5/0x120 kernel/printk/printk.c:2367
> register_console+0x70a/0xcd0 kernel/printk/printk.c:3548
> univ8250_console_init+0x49/0x50 drivers/tty/serial/8250/8250_core.c:717
> console_init+0x198/0x680 kernel/printk/printk.c:3694
> start_kernel+0x2d3/0x500 init/main.c:1012
> x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:509
> x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:490
> common_startup_64+0x13e/0x147
>
> -> #0 (console_owner
> ){-...}-{0:0}:
> check_prev_add kernel/locking/lockdep.c:3134 [inline]
> check_prevs_add kernel/locking/lockdep.c:3253 [inline]
> validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
> __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
> lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
> console_trylock_spinning kernel/printk/printk.c:1997 [inline]
> vprintk_emit+0x3f3/0x770 kernel/printk/printk.c:2341
> _printk+0xd5/0x120 kernel/printk/printk.c:2367
> __report_bug lib/bug.c:195 [inline]
> report_bug+0x346/0x500 lib/bug.c:219
> handle_bug+0x3e/0x70 arch/x86/kernel/traps.c:239
> exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:260
> asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621
> __local_bh_disable_ip+0x1f6/0x220 kernel/softirq.c:307
> __raw_spin_lock_bh include/linux/spinlock_api_smp.h:125 [inline]
> _raw_spin_lock_bh+0x1c/0x50 kernel/locking/spinlock.c:178
> spin_lock_bh include/linux/spinlock.h:356 [inline]
> __sock_map_delete net/core/sock_map.c:414 [inline]
> sock_map_delete_elem+0x97/0x140 net/core/sock_map.c:446
> bpf_prog_2c29ac5cdc6b1842+0x42/0x4a
> bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
> __bpf_prog_run include/linux/filter.h:657 [inline]
> bpf_prog_run include/linux/filter.h:664 [inline]
> __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
> bpf_trace_run4+0x25c/0x490 kernel/trace/bpf_trace.c:2422
> trace_mm_page_alloc include/trace/events/kmem.h:177 [inline]
> __alloc_pages+0x657/0x680 mm/page_alloc.c:4591
> __alloc_pages_node include/linux/gfp.h:238 [inline]
> alloc_pages_node include/linux/gfp.h:261 [inline]
> alloc_slab_page+0x5f/0x160 mm/slub.c:2175
> allocate_slab mm/slub.c:2338 [inline]
> new_slab+0x84/0x2f0 mm/slub.c:2391
> ___slab_alloc+0xc73/0x1260 mm/slub.c:3525
> __slab_alloc mm/slub.c:3610 [inline]
> __slab_alloc_node mm/slub.c:3663 [inline]
> slab_alloc_node mm/slub.c:3835 [inline]
> kmem_cache_alloc+0x252/0x340 mm/slub.c:3852
> kmem_cache_zalloc include/linux/slab.h:739 [inline]
> fill_pool lib/debugobjects.c:168 [inline]
> debug_objects_fill_pool+0x52b/0x9b0 lib/debugobjects.c:615
> debug_object_activate+0x135/0x510 lib/debugobjects.c:704
> debug_hrtimer_activate kernel/time/hrtimer.c:423 [inline]
> debug_activate kernel/time/hrtimer.c:478 [inline]
> enqueue_hrtimer+0x30/0x3a0 kernel/time/hrtimer.c:1090
> __run_hrtimer kernel/time/hrtimer.c:1709 [inline]
> __hrtimer_run_queues+0x6b5/0xd00 kernel/time/hrtimer.c:1756
> hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1818
> local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline]
> __sysvec_apic_timer_interrupt+0x109/0x3a0 arch/x86/kernel/apic/apic.c:1049
> instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
> sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043
> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
> srso_safe_ret+0x0/0x20
> srso_return_thunk+0x5/0x5f arch/x86/lib/retpoline.S:222
> unwind_next_frame+0xc1/0x2a00 arch/x86/kernel/unwind_orc.c:479
> __unwind_start+0x641/0x7c0 arch/x86/kernel/unwind_orc.c:760
> unwind_start arch/x86/include/asm/unwind.h:64 [inline]
> arch_stack_walk+0x103/0x1b0 arch/x86/kernel/stacktrace.c:24
> stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
> kasan_save_stack mm/kasan/common.c:47 [inline]
> kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
> unpoison_slab_object mm/kasan/common.c:312 [inline]
> __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338
> kasan_slab_alloc include/linux/kasan.h:201 [inline]
> slab_post_alloc_hook mm/slub.c:3798 [inline]
> slab_alloc_node mm/slub.c:3845 [inline]
> kmem_cache_alloc+0x174/0x340 mm/slub.c:3852
> kmem_cache_zalloc include/linux/slab.h:739 [inline]
> fill_pool lib/debugobjects.c:168 [inline]
> debug_objects_fill_pool+0x4ec/0x9b0 lib/debugobjects.c:615
> debug_object_activate+0x135/0x510 lib/debugobjects.c:704
> debug_rcu_head_queue kernel/rcu/rcu.h:227 [inline]
> __call_rcu_common kernel/rcu/tree.c:2719 [inline]
> call_rcu+0x97/0xa70 kernel/rcu/tree.c:2838
> __dentry_kill+0x20d/0x630 fs/dcache.c:603
> shrink_kill+0xa9/0x2c0 fs/dcache.c:1048
> shrink_dentry_list+0x2c0/0x5b0 fs/dcache.c:1075
> prune_dcache_sb+0x10f/0x180 fs/dcache.c:1156
> super_cache_scan+0x34f/0x4b0 fs/super.c:221
> do_shrink_slab+0x6d2/0x1140 mm/shrinker.c:435
> shrink_slab+0x1092/0x14d0 mm/shrinker.c:662
> shrink_one+0x423/0x7f0 mm/vmscan.c:4767
> shrink_many mm/vmscan.c:4828 [inline]
> lru_gen_shrink_node mm/vmscan.c:4929 [inline]
> shrink_node+0x37b8/0x3e70 mm/vmscan.c:5888
> kswapd_shrink_node mm/vmscan.c:6696 [inline]
> balance_pgdat mm/vmscan.c:6886 [inline]
> kswapd+0x17d1/0x36e0 mm/vmscan.c:7146
> kthread+0x2f2/0x390 kernel/kthread.c:388
> ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
>
> other info that might help us debug this:
>
> Chain exists of:
> console_owner --> &dev->power.lock --> hrtimer_bases.lock
>
> Possible unsafe locking scenario:
>
> CPU0 CPU1
> ---- ----
> lock(hrtimer_bases.lock);
> lock(&dev->power.lock);
> lock(hrtimer_bases.lock);
> lock(console_owner);
>
> *** DEADLOCK ***
>
> 6 locks held by kswapd0/88:
> #0: ffffffff8e21f720
> (fs_reclaim){+.+.}-{0:0}
> , at: balance_pgdat mm/vmscan.c:6774 [inline]
> , at: kswapd+0xb3f/0x36e0 mm/vmscan.c:7146
> #1:
> ffff88802f9d80e0 (&type->s_umount_key#52){.+.+}-{3:3}
> , at: super_trylock_shared fs/super.c:561 [inline]
> , at: super_cache_scan+0x94/0x4b0 fs/super.c:196
> #2: ffffffff8e81bb40
> (fill_pool_map-wait-type-override){+.+.}-{3:3}
> , at: debug_objects_fill_pool+0x80/0x9b0 lib/debugobjects.c:614
> #3: ffff8880b952c8d8
> (hrtimer_bases.lock){-.-.}-{2:2}
> , at: __run_hrtimer kernel/time/hrtimer.c:1696 [inline]
> , at: __hrtimer_run_queues+0x65a/0xd00 kernel/time/hrtimer.c:1756
> #4: ffffffff8e81bb40
> (fill_pool_map-wait-type-override){+.+.}-{3:3}
> , at: debug_objects_fill_pool+0x80/0x9b0 lib/debugobjects.c:614

Given nested acquiring of fill_pool_map-wait-type-override without
any lockdep warning triggered, could locking people shed light on the
sense it may make? IOW why is it needed?

Hillf

> #5: ffffffff8e132020 (
> rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
> rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
> rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline]
> rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x16e/0x490 kernel/trace/bpf_trace.c:2422