syzbot


possible deadlock in pwq_dec_nr_in_flight

Status: upstream: reported on 2024/04/14 11:10
Subsystems: trace bpf
[Documentation on labels]
Reported-by: syzbot+92438ab91cb6348b16fa@syzkaller.appspotmail.com
Fix commit: ff9105993240 bpf, sockmap: Prevent lock inversion deadlock in map delete elem
Patched on: [ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-net-next-test-gce ci2-upstream-usb], missing on: [ci-qemu2-riscv64]
First crash: 41d, last: 41d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [trace?] [bpf?] possible deadlock in pwq_dec_nr_in_flight 1 (2) 2024/04/20 15:56

Sample crash report:
------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted
------------------------------------------------------
kworker/u8:5/987 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:
ffff8881483629a0 (&nna->lock){..-.}-{2:2}, at: node_activate_pending_pwq kernel/workqueue.c:1882 [inline]
ffff8881483629a0 (&nna->lock){..-.}-{2:2}, at: pwq_dec_nr_active kernel/workqueue.c:1993 [inline]
ffff8881483629a0 (&nna->lock){..-.}-{2:2}, at: pwq_dec_nr_in_flight+0x32a/0xd60 kernel/workqueue.c:2017

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&nna->lock){..-.}-{2:2}:
       lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
       pwq_tryinc_nr_active+0x2ef/0x720 kernel/workqueue.c:1774
       __queue_work+0xa9d/0xec0 kernel/workqueue.c:2395
       queue_work_on+0x14f/0x250 kernel/workqueue.c:2435
       queue_work include/linux/workqueue.h:605 [inline]
       call_usermodehelper_exec+0x286/0x4a0 kernel/umh.c:434
       kobject_uevent_env+0x6b5/0x8f0 lib/kobject_uevent.c:618
       driver_register+0x2d6/0x320 drivers/base/driver.c:254
       pcie_init_services+0xa/0x20 drivers/pci/pcie/portdrv.c:828
       pcie_portdrv_init+0x38/0x60 drivers/pci/pcie/portdrv.c:839
       do_one_initcall+0x238/0x830 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+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

-> #3 (&pool->lock){-.-.}-{2:2}:
       lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
       __queue_work+0x6ec/0xec0
       queue_work_on+0x14f/0x250 kernel/workqueue.c:2435
       queue_work include/linux/workqueue.h:605 [inline]
       rpm_suspend+0xe99/0x1780 drivers/base/power/runtime.c:662
       __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
       serial_base_port_add+0x2b6/0x3f0 drivers/tty/serial/serial_base_bus.c:178
       serial_core_port_device_add drivers/tty/serial/serial_core.c:3353 [inline]
       serial_core_register_port+0x393/0x1e30 drivers/tty/serial/serial_core.c:3394
       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+0x2ba/0x460 drivers/pnp/driver.c:111
       really_probe+0x29e/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+0x239/0x2b0 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+0x238/0x830 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+0x4b/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+0xd6a/0x1230 drivers/tty/n_tty.c:2379
       iterate_tty_write drivers/tty/tty_io.c:1021 [inline]
       file_tty_write+0x54f/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+0xa84/0xcb0 fs/read_write.c:590
       ksys_write+0x1a0/0x2c0 fs/read_write.c:643
       do_syscall_64+0xfb/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_enable_ip+0x1be/0x200 kernel/softirq.c:362
       spin_unlock_bh include/linux/spinlock.h:396 [inline]
       __sock_map_delete net/core/sock_map.c:424 [inline]
       sock_map_delete_elem+0xca/0x140 net/core/sock_map.c:446
       bpf_prog_f4780399ec52412a+0x45/0x49
       bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
       __bpf_prog_run include/linux/filter.h:650 [inline]
       bpf_prog_run include/linux/filter.h:664 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
       bpf_trace_run1+0x336/0x3f0 kernel/trace/bpf_trace.c:2419
       trace_workqueue_activate_work+0x161/0x1d0 include/trace/events/workqueue.h:59
       __pwq_activate_work+0x61/0x340 kernel/workqueue.c:1675
       node_activate_pending_pwq kernel/workqueue.c:1926 [inline]
       pwq_dec_nr_active kernel/workqueue.c:1993 [inline]
       pwq_dec_nr_in_flight+0x679/0xd60 kernel/workqueue.c:2017
       process_one_work kernel/workqueue.c:3309 [inline]
       process_scheduled_works+0xec5/0x1770 kernel/workqueue.c:3335
       worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
       kthread+0x2f0/0x390 kernel/kthread.c:388
       ret_from_fork+0x4b/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 --> &pool->lock --> &nna->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&nna->lock);
                               lock(&pool->lock);
                               lock(&nna->lock);
  lock(console_owner);

 *** DEADLOCK ***

3 locks held by kworker/u8:5/987:
 #0: ffff888014ca0018 (&pool->lock){-.-.}-{2:2}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff888014ca0018 (&pool->lock){-.-.}-{2:2}, at: process_scheduled_works+0xc90/0x1770 kernel/workqueue.c:3335
 #1: ffff8881483629a0 (&nna->lock){..-.}-{2:2}, at: node_activate_pending_pwq kernel/workqueue.c:1882 [inline]
 #1: ffff8881483629a0 (&nna->lock){..-.}-{2:2}, at: pwq_dec_nr_active kernel/workqueue.c:1993 [inline]
 #1: ffff8881483629a0 (&nna->lock){..-.}-{2:2}, at: pwq_dec_nr_in_flight+0x32a/0xd60 kernel/workqueue.c:2017
 #2: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #2: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
 #2: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline]
 #2: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run1+0xf0/0x3f0 kernel/trace/bpf_trace.c:2419

stack backtrace:
CPU: 0 PID: 987 Comm: kworker/u8:5 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue:  0x0 (bat_events)
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187
 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
RIP: 0010:__local_bh_enable_ip+0x1be/0x200 kernel/softirq.c:362
Code: 3b 44 24 60 75 52 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc 90 0f 0b 90 e9 ca fe ff ff e8 55 00 00 00 eb 9c 90 <0f> 0b 90 e9 fa fe ff ff 48 c7 c1 0c 41 86 8f 80 e1 07 80 c1 03 38
RSP: 0018:ffffc9000404f8c0 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 1ffff92000809f1c RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000201 RDI: ffffffff895b48fa
RBP: ffffc9000404f980 R08: ffff88805c7049eb R09: 1ffff1100b8e093d
R10: dffffc0000000000 R11: ffffed100b8e093e R12: dffffc0000000000
R13: ffff88807ca940c0 R14: ffffc9000404f900 R15: 0000000000000201
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 __sock_map_delete net/core/sock_map.c:424 [inline]
 sock_map_delete_elem+0xca/0x140 net/core/sock_map.c:446
 bpf_prog_f4780399ec52412a+0x45/0x49
 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
 __bpf_prog_run include/linux/filter.h:650 [inline]
 bpf_prog_run include/linux/filter.h:664 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
 bpf_trace_run1+0x336/0x3f0 kernel/trace/bpf_trace.c:2419
 trace_workqueue_activate_work+0x161/0x1d0 include/trace/events/workqueue.h:59
 __pwq_activate_work+0x61/0x340 kernel/workqueue.c:1675
 node_activate_pending_pwq kernel/workqueue.c:1926 [inline]
 pwq_dec_nr_active kernel/workqueue.c:1993 [inline]
 pwq_dec_nr_in_flight+0x679/0xd60 kernel/workqueue.c:2017
 process_one_work kernel/workqueue.c:3309 [inline]
 process_scheduled_works+0xec5/0x1770 kernel/workqueue.c:3335
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>
WARNING: CPU: 0 PID: 987 at kernel/softirq.c:362 __local_bh_enable_ip+0x1be/0x200 kernel/softirq.c:362
Modules linked in:
CPU: 0 PID: 987 Comm: kworker/u8:5 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue:  0x0 (bat_events)
RIP: 0010:__local_bh_enable_ip+0x1be/0x200 kernel/softirq.c:362
Code: 3b 44 24 60 75 52 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc 90 0f 0b 90 e9 ca fe ff ff e8 55 00 00 00 eb 9c 90 <0f> 0b 90 e9 fa fe ff ff 48 c7 c1 0c 41 86 8f 80 e1 07 80 c1 03 38
RSP: 0018:ffffc9000404f8c0 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 1ffff92000809f1c RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000201 RDI: ffffffff895b48fa
RBP: ffffc9000404f980 R08: ffff88805c7049eb R09: 1ffff1100b8e093d
R10: dffffc0000000000 R11: ffffed100b8e093e R12: dffffc0000000000
R13: ffff88807ca940c0 R14: ffffc9000404f900 R15: 0000000000000201
FS:  0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc8ff1abf84 CR3: 0000000062f64000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 __sock_map_delete net/core/sock_map.c:424 [inline]
 sock_map_delete_elem+0xca/0x140 net/core/sock_map.c:446
 bpf_prog_f4780399ec52412a+0x45/0x49
 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
 __bpf_prog_run include/linux/filter.h:650 [inline]
 bpf_prog_run include/linux/filter.h:664 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
 bpf_trace_run1+0x336/0x3f0 kernel/trace/bpf_trace.c:2419
 trace_workqueue_activate_work+0x161/0x1d0 include/trace/events/workqueue.h:59
 __pwq_activate_work+0x61/0x340 kernel/workqueue.c:1675
 node_activate_pending_pwq kernel/workqueue.c:1926 [inline]
 pwq_dec_nr_active kernel/workqueue.c:1993 [inline]
 pwq_dec_nr_in_flight+0x679/0xd60 kernel/workqueue.c:2017
 process_one_work kernel/workqueue.c:3309 [inline]
 process_scheduled_works+0xec5/0x1770 kernel/workqueue.c:3335
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/10 11:04 upstream fe46a7dd189e 56086b24 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root possible deadlock in pwq_dec_nr_in_flight
* Struck through repros no longer work on HEAD.