======================================================== WARNING: possible irq lock inversion dependency detected 5.9.0-syzkaller #0 Not tainted -------------------------------------------------------- kworker/u4:5/213 just changed the state of lock: ffff888214f60908 (&group->lock){..-.}-{2:2}, at: snd_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1799 but this lock took another, SOFTIRQ-READ-unsafe lock in the past: (&card->ctl_files_rwlock){.+.+}-{2:2} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&card->ctl_files_rwlock); local_irq_disable(); lock(&group->lock); lock(&card->ctl_files_rwlock); lock(&group->lock); *** DEADLOCK *** 3 locks held by kworker/u4:5/213: #0: ffff888214a91138 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x6f4/0xfc0 kernel/workqueue.c:2242 #1: ffffc90000ef7d80 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x733/0xfc0 kernel/workqueue.c:2244 #2: ffffc90000007db0 ((&dpcm->timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:45 [inline] #2: ffffc90000007db0 ((&dpcm->timer)){+.-.}-{0:0}, at: call_timer_fn+0x57/0x160 kernel/time/timer.c:1405 the shortest dependencies between 2nd lock and 1st lock: -> (&card->ctl_files_rwlock){.+.+}-{2:2} { HARDIRQ-ON-R at: lock_acquire+0x160/0x710 kernel/locking/lockdep.c:5442 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 snd_ctl_notify+0x86/0x550 sound/core/control.c:153 __snd_ctl_add_replace+0x582/0x8a0 sound/core/control.c:382 snd_ctl_add_replace sound/core/control.c:399 [inline] snd_ctl_add+0x6e/0x110 sound/core/control.c:426 snd_card_dummy_new_mixer sound/drivers/dummy.c:885 [inline] snd_dummy_probe+0xb9e/0x1000 sound/drivers/dummy.c:1080 platform_drv_probe+0xcd/0x150 drivers/base/platform.c:747 really_probe+0x753/0x1110 drivers/base/dd.c:557 driver_probe_device+0x106/0x1a0 drivers/base/dd.c:738 bus_for_each_drv+0x108/0x170 drivers/base/bus.c:431 __device_attach+0x262/0x3f0 drivers/base/dd.c:912 bus_probe_device+0xb8/0x1f0 drivers/base/bus.c:491 device_add+0x1630/0x19b0 drivers/base/core.c:2926 platform_device_add+0x4ad/0x6e0 drivers/base/platform.c:597 platform_device_register_full+0x448/0x530 drivers/base/platform.c:720 platform_device_register_resndata include/linux/platform_device.h:131 [inline] platform_device_register_simple include/linux/platform_device.h:160 [inline] alsa_card_dummy_init+0x1b3/0x398 sound/drivers/dummy.c:1168 do_one_initcall+0x14b/0x350 init/main.c:1205 do_initcall_level+0x101/0x14c init/main.c:1278 do_initcalls+0x59/0x9b init/main.c:1294 kernel_init_freeable+0x356/0x474 init/main.c:1514 kernel_init+0xd/0x290 init/main.c:1403 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 SOFTIRQ-ON-R at: lock_acquire+0x160/0x710 kernel/locking/lockdep.c:5442 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 snd_ctl_notify+0x86/0x550 sound/core/control.c:153 __snd_ctl_add_replace+0x582/0x8a0 sound/core/control.c:382 snd_ctl_add_replace sound/core/control.c:399 [inline] snd_ctl_add+0x6e/0x110 sound/core/control.c:426 snd_card_dummy_new_mixer sound/drivers/dummy.c:885 [inline] snd_dummy_probe+0xb9e/0x1000 sound/drivers/dummy.c:1080 platform_drv_probe+0xcd/0x150 drivers/base/platform.c:747 really_probe+0x753/0x1110 drivers/base/dd.c:557 driver_probe_device+0x106/0x1a0 drivers/base/dd.c:738 bus_for_each_drv+0x108/0x170 drivers/base/bus.c:431 __device_attach+0x262/0x3f0 drivers/base/dd.c:912 bus_probe_device+0xb8/0x1f0 drivers/base/bus.c:491 device_add+0x1630/0x19b0 drivers/base/core.c:2926 platform_device_add+0x4ad/0x6e0 drivers/base/platform.c:597 platform_device_register_full+0x448/0x530 drivers/base/platform.c:720 platform_device_register_resndata include/linux/platform_device.h:131 [inline] platform_device_register_simple include/linux/platform_device.h:160 [inline] alsa_card_dummy_init+0x1b3/0x398 sound/drivers/dummy.c:1168 do_one_initcall+0x14b/0x350 init/main.c:1205 do_initcall_level+0x101/0x14c init/main.c:1278 do_initcalls+0x59/0x9b init/main.c:1294 kernel_init_freeable+0x356/0x474 init/main.c:1514 kernel_init+0xd/0x290 init/main.c:1403 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 INITIAL READ USE at: lock_acquire+0x160/0x710 kernel/locking/lockdep.c:5442 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 snd_ctl_notify+0x86/0x550 sound/core/control.c:153 __snd_ctl_add_replace+0x582/0x8a0 sound/core/control.c:382 snd_ctl_add_replace sound/core/control.c:399 [inline] snd_ctl_add+0x6e/0x110 sound/core/control.c:426 snd_card_dummy_new_mixer sound/drivers/dummy.c:885 [inline] snd_dummy_probe+0xb9e/0x1000 sound/drivers/dummy.c:1080 platform_drv_probe+0xcd/0x150 drivers/base/platform.c:747 really_probe+0x753/0x1110 drivers/base/dd.c:557 driver_probe_device+0x106/0x1a0 drivers/base/dd.c:738 bus_for_each_drv+0x108/0x170 drivers/base/bus.c:431 __device_attach+0x262/0x3f0 drivers/base/dd.c:912 bus_probe_device+0xb8/0x1f0 drivers/base/bus.c:491 device_add+0x1630/0x19b0 drivers/base/core.c:2926 platform_device_add+0x4ad/0x6e0 drivers/base/platform.c:597 platform_device_register_full+0x448/0x530 drivers/base/platform.c:720 platform_device_register_resndata include/linux/platform_device.h:131 [inline] platform_device_register_simple include/linux/platform_device.h:160 [inline] alsa_card_dummy_init+0x1b3/0x398 sound/drivers/dummy.c:1168 do_one_initcall+0x14b/0x350 init/main.c:1205 do_initcall_level+0x101/0x14c init/main.c:1278 do_initcalls+0x59/0x9b init/main.c:1294 kernel_init_freeable+0x356/0x474 init/main.c:1514 kernel_init+0xd/0x290 init/main.c:1403 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 } ... key at: [] snd_card_new.__key.3+0x0/0x10 ... acquired at: lock_acquire+0x160/0x710 kernel/locking/lockdep.c:5442 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 snd_ctl_notify+0x86/0x550 sound/core/control.c:153 loopback_check_format sound/drivers/aloop.c:353 [inline] loopback_trigger+0xb75/0x1500 sound/drivers/aloop.c:387 snd_pcm_do_start sound/core/pcm_native.c:1350 [inline] snd_pcm_action_single sound/core/pcm_native.c:1207 [inline] snd_pcm_action sound/core/pcm_native.c:1290 [inline] snd_pcm_start+0x471/0x6c0 sound/core/pcm_native.c:1391 __snd_pcm_lib_xfer+0xf73/0x1320 sound/core/pcm_lib.c:2247 snd_pcm_oss_write3+0x209/0x330 sound/core/oss/pcm_oss.c:1221 snd_pcm_oss_write2+0x1bb/0x370 sound/core/oss/pcm_oss.c:1361 snd_pcm_oss_write1 sound/core/oss/pcm_oss.c:1419 [inline] snd_pcm_oss_write+0x911/0xd70 sound/core/oss/pcm_oss.c:2765 vfs_write+0x2d3/0xd10 fs/read_write.c:584 ksys_write+0x11b/0x220 fs/read_write.c:639 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> (&group->lock){..-.}-{2:2} { IN-SOFTIRQ-W at: lock_acquire+0x160/0x710 kernel/locking/lockdep.c:5442 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xaa/0xd0 kernel/locking/spinlock.c:159 snd_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1799 call_timer_fn+0x91/0x160 kernel/time/timer.c:1415 expire_timers kernel/time/timer.c:1460 [inline] __run_timers+0x65e/0x830 kernel/time/timer.c:1757 run_timer_softirq+0x46/0x80 kernel/time/timer.c:1770 __do_softirq+0x256/0x6e0 kernel/softirq.c:298 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0x9a/0xf0 arch/x86/kernel/irq_64.c:77 do_softirq+0x102/0x150 kernel/softirq.c:343 __local_bh_enable_ip+0x183/0x1d0 kernel/softirq.c:195 spin_unlock_bh include/linux/spinlock.h:399 [inline] batadv_nc_purge_paths+0x36f/0x400 net/batman-adv/network-coding.c:470 batadv_nc_worker+0x2ea/0x5c0 net/batman-adv/network-coding.c:719 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 INITIAL USE at: lock_acquire+0x160/0x710 kernel/locking/lockdep.c:5442 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0xa6/0xc0 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:379 [inline] snd_pcm_group_lock_irq sound/core/pcm_native.c:97 [inline] snd_pcm_stream_lock_irq sound/core/pcm_native.c:136 [inline] snd_pcm_hw_params+0xca/0x16b0 sound/core/pcm_native.c:672 snd_pcm_oss_change_params_locked+0x25e0/0x4410 sound/core/oss/pcm_oss.c:941 snd_pcm_oss_make_ready_locked sound/core/oss/pcm_oss.c:1166 [inline] snd_pcm_oss_write1 sound/core/oss/pcm_oss.c:1384 [inline] snd_pcm_oss_write+0x269/0xd70 sound/core/oss/pcm_oss.c:2765 vfs_write+0x2d3/0xd10 fs/read_write.c:584 ksys_write+0x11b/0x220 fs/read_write.c:639 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 } ... key at: [] snd_pcm_group_init.__key+0x0/0x10 ... acquired at: mark_usage kernel/locking/lockdep.c:4305 [inline] __lock_acquire+0xa67/0x2bd0 kernel/locking/lockdep.c:4791 lock_acquire+0x160/0x710 kernel/locking/lockdep.c:5442 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xaa/0xd0 kernel/locking/spinlock.c:159 snd_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1799 call_timer_fn+0x91/0x160 kernel/time/timer.c:1415 expire_timers kernel/time/timer.c:1460 [inline] __run_timers+0x65e/0x830 kernel/time/timer.c:1757 run_timer_softirq+0x46/0x80 kernel/time/timer.c:1770 __do_softirq+0x256/0x6e0 kernel/softirq.c:298 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0x9a/0xf0 arch/x86/kernel/irq_64.c:77 do_softirq+0x102/0x150 kernel/softirq.c:343 __local_bh_enable_ip+0x183/0x1d0 kernel/softirq.c:195 spin_unlock_bh include/linux/spinlock.h:399 [inline] batadv_nc_purge_paths+0x36f/0x400 net/batman-adv/network-coding.c:470 batadv_nc_worker+0x2ea/0x5c0 net/batman-adv/network-coding.c:719 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 stack backtrace: CPU: 0 PID: 213 Comm: kworker/u4:5 Not tainted 5.9.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d6/0x29e lib/dump_stack.c:118 print_irq_inversion_bug+0xa5c/0xd70 kernel/locking/lockdep.c:3817 check_usage_forwards kernel/locking/lockdep.c:191 [inline] mark_lock_irq kernel/locking/lockdep.c:3980 [inline] mark_lock+0xe80/0x2050 kernel/locking/lockdep.c:4408 mark_usage kernel/locking/lockdep.c:4305 [inline] __lock_acquire+0xa67/0x2bd0 kernel/locking/lockdep.c:4791 lock_acquire+0x160/0x710 kernel/locking/lockdep.c:5442 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xaa/0xd0 kernel/locking/spinlock.c:159 snd_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1799 call_timer_fn+0x91/0x160 kernel/time/timer.c:1415 expire_timers kernel/time/timer.c:1460 [inline] __run_timers+0x65e/0x830 kernel/time/timer.c:1757 run_timer_softirq+0x46/0x80 kernel/time/timer.c:1770 __do_softirq+0x256/0x6e0 kernel/softirq.c:298 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0x9a/0xf0 arch/x86/kernel/irq_64.c:77 do_softirq+0x102/0x150 kernel/softirq.c:343 __local_bh_enable_ip+0x183/0x1d0 kernel/softirq.c:195 spin_unlock_bh include/linux/spinlock.h:399 [inline] batadv_nc_purge_paths+0x36f/0x400 net/batman-adv/network-coding.c:470 batadv_nc_worker+0x2ea/0x5c0 net/batman-adv/network-coding.c:719 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294