md/raid:md0: PPL space too small on ram1
=============================================================================
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.6.2074/14113 is trying to acquire lock:
ffffffff8d1263e0 (console_owner){-...}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:339 [inline]
ffffffff8d1263e0 (console_owner){-...}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:232 [inline]
ffffffff8d1263e0 (console_owner){-...}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:292 [inline]
ffffffff8d1263e0 (console_owner){-...}-{0:0}, at: console_flush_all+0x10b/0xcf0 kernel/printk/printk.c:2992

but task is already holding lock:
ffff88802e046f18 (&n->list_lock){-.-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline]
ffff88802e046f18 (&n->list_lock){-.-.}-{2:2}, at: free_partial mm/slub.c:4623 [inline]
ffff88802e046f18 (&n->list_lock){-.-.}-{2:2}, at: __kmem_cache_shutdown+0x98/0x230 mm/slub.c:4661

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&n->list_lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
       get_partial_node+0x36/0x550 mm/slub.c:2301
       get_partial mm/slub.c:2416 [inline]
       ___slab_alloc+0x9cc/0x12f0 mm/slub.c:3230
       __slab_alloc mm/slub.c:3339 [inline]
       __slab_alloc_node mm/slub.c:3392 [inline]
       slab_alloc_node mm/slub.c:3485 [inline]
       __kmem_cache_alloc_node+0x11f/0x250 mm/slub.c:3534
       __do_kmalloc_node mm/slab_common.c:1006 [inline]
       __kmalloc+0xa7/0x240 mm/slab_common.c:1020
       kmalloc include/linux/slab.h:604 [inline]
       tty_buffer_alloc drivers/tty/tty_buffer.c:180 [inline]
       __tty_buffer_request_room+0x1bf/0x500 drivers/tty/tty_buffer.c:273
       __tty_insert_flip_string_flags+0xb9/0x430 drivers/tty/tty_buffer.c:309
       tty_insert_flip_string_fixed_flag include/linux/tty_flip.h:35 [inline]
       tty_insert_flip_string include/linux/tty_flip.h:83 [inline]
       tty_insert_flip_string_and_push_buffer+0xa5/0x1f0 drivers/tty/tty_buffer.c:559
       pty_write+0xa3/0xe0 drivers/tty/pty.c:118
       n_tty_write+0x5e0/0x11e0 drivers/tty/n_tty.c:2417
       iterate_tty_write drivers/tty/tty_io.c:1017 [inline]
       file_tty_write+0x529/0x960 drivers/tty/tty_io.c:1088
       call_write_iter include/linux/fs.h:2018 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x474/0x9a0 fs/read_write.c:584
       ksys_write+0x151/0x260 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #2 (&port->lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
       tty_port_tty_get drivers/tty/tty_port.c:325 [inline]
       tty_port_default_wakeup+0x21/0xf0 drivers/tty/tty_port.c:66
       serial8250_tx_chars+0x6a2/0x8b0 drivers/tty/serial/8250/8250_port.c:1837
       serial8250_handle_irq+0x567/0x730 drivers/tty/serial/8250/8250_port.c:1944
       serial8250_default_handle_irq+0xb8/0x1a0 drivers/tty/serial/8250/8250_port.c:1964
       serial8250_interrupt+0x9f/0x1c0 drivers/tty/serial/8250/8250_core.c:127
       __handle_irq_event_percpu+0x271/0x940 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:210
       handle_edge_irq+0x246/0xb20 kernel/irq/chip.c:831
       generic_handle_irq_desc include/linux/irqdesc.h:161 [inline]
       handle_irq arch/x86/kernel/irq.c:240 [inline]
       __common_interrupt+0x13b/0x230 arch/x86/kernel/irq.c:259
       common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:249
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:678
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
       _raw_spin_unlock_irqrestore+0xc0/0x120 kernel/locking/spinlock.c:194
       spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
       uart_write+0x45b/0x5d0 drivers/tty/serial/serial_core.c:634
       process_output_block drivers/tty/n_tty.c:580 [inline]
       n_tty_write+0xd3d/0x11e0 drivers/tty/n_tty.c:2395
       iterate_tty_write drivers/tty/tty_io.c:1017 [inline]
       file_tty_write+0x529/0x960 drivers/tty/tty_io.c:1088
       call_write_iter include/linux/fs.h:2018 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x474/0x9a0 fs/read_write.c:584
       ksys_write+0x151/0x260 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (&port_lock_key){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
       serial8250_console_write+0x181/0x18b0 drivers/tty/serial/8250/8250_port.c:3439
       console_emit_next_record kernel/printk/printk.c:2944 [inline]
       console_flush_all+0x6ad/0xcf0 kernel/printk/printk.c:3000
       console_unlock+0xad/0x350 kernel/printk/printk.c:3069
       vprintk_emit+0x497/0x610 kernel/printk/printk.c:2341
       _printk+0xde/0x130 kernel/printk/printk.c:2366
       register_console+0xb96/0xf00 kernel/printk/printk.c:3583
       univ8250_console_init+0x45/0x50 drivers/tty/serial/8250/8250_core.c:717
       console_init+0x17b/0x5d0 kernel/printk/printk.c:3726
       start_kernel+0x2c8/0x4e0 init/main.c:982
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
       copy_bootdata+0x0/0xd0 arch/x86/kernel/head64.c:536
       secondary_startup_64_no_verify+0x179/0x17b

-> #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 kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
       lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5756
       console_lock_spinning_enable kernel/printk/printk.c:1871 [inline]
       console_emit_next_record kernel/printk/printk.c:2938 [inline]
       console_flush_all+0x676/0xcf0 kernel/printk/printk.c:3000
       console_unlock+0xad/0x350 kernel/printk/printk.c:3069
       vprintk_emit+0x497/0x610 kernel/printk/printk.c:2341
       _printk+0xde/0x130 kernel/printk/printk.c:2366
       slab_bug+0x6d/0xc0 mm/slub.c:920
       slab_err+0x130/0x170 mm/slub.c:1026
       list_slab_objects+0x38/0x1a0 mm/slub.c:4596
       free_partial mm/slub.c:4629 [inline]
       __kmem_cache_shutdown+0x132/0x230 mm/slub.c:4661
       shutdown_cache mm/slab_common.c:457 [inline]
       kmem_cache_destroy+0x56/0x160 mm/slab_common.c:497
       shrink_stripes drivers/md/raid5.c:2726 [inline]
       free_conf+0x227/0x4b0 drivers/md/raid5.c:7442
       raid5_run+0x23a5/0x2a00 drivers/md/raid5.c:8150
       level_store+0x1646/0x1a90 drivers/md/md.c:4128
       md_attr_store+0x196/0x380 drivers/md/md.c:5637
       kernfs_fop_write_iter+0x3a4/0x520 fs/kernfs/file.c:352
       call_write_iter include/linux/fs.h:2018 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x474/0x9a0 fs/read_write.c:584
       ksys_write+0x151/0x260 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

Chain exists of:
  console_owner --> &port->lock --> &n->list_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&n->list_lock);
                               lock(&port->lock);
                               lock(&n->list_lock);
  lock(console_owner);

 *** DEADLOCK ***

10 locks held by syz.6.2074/14113:
 #0: ffff8880211ad748 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
 #1: ffff88806a82c418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
 #2: ffff888061bf8c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
 #3: ffff8880222486d0 (kn->active#76){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #3: ffff8880222486d0 (kn->active#76){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
 #4: ffff8880773302d0 (&mddev->reconfig_mutex){+.+.}-{3:3}, at: mddev_lock drivers/md/md.h:592 [inline]
 #4: ffff8880773302d0 (&mddev->reconfig_mutex){+.+.}-{3:3}, at: level_store+0xd0/0x1a90 drivers/md/md.c:3951
 #5: ffffffff8cfcd450 (cpu_hotplug_lock){++++}-{0:0}, at: kmem_cache_destroy+0x30/0x160 mm/slab_common.c:488
 #6: ffffffff8d200b58 (slab_mutex){+.+.}-{3:3}, at: kmem_cache_destroy+0x3e/0x160 mm/slab_common.c:489
 #7: ffff88802e046f18 (&n->list_lock){-.-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline]
 #7: ffff88802e046f18 (&n->list_lock){-.-.}-{2:2}, at: free_partial mm/slub.c:4623 [inline]
 #7: ffff88802e046f18 (&n->list_lock){-.-.}-{2:2}, at: __kmem_cache_shutdown+0x98/0x230 mm/slub.c:4661
 #8: ffffffff8d1264c0 (console_lock){+.+.}-{0:0}, at: _printk+0xde/0x130 kernel/printk/printk.c:2366
 #9: ffffffff8d00dcd0 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:339 [inline]
 #9: ffffffff8d00dcd0 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:232 [inline]
 #9: ffffffff8d00dcd0 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:292 [inline]
 #9: ffffffff8d00dcd0 (console_srcu){....}-{0:0}, at: console_flush_all+0x10b/0xcf0 kernel/printk/printk.c:2992

stack backtrace:
CPU: 0 PID: 14113 Comm: syz.6.2074 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 check_noncircular+0x2fc/0x400 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 kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5756
 console_lock_spinning_enable kernel/printk/printk.c:1871 [inline]
 console_emit_next_record kernel/printk/printk.c:2938 [inline]
 console_flush_all+0x676/0xcf0 kernel/printk/printk.c:3000
 console_unlock+0xad/0x350 kernel/printk/printk.c:3069
 vprintk_emit+0x497/0x610 kernel/printk/printk.c:2341
 _printk+0xde/0x130 kernel/printk/printk.c:2366
 slab_bug+0x6d/0xc0 mm/slub.c:920
 slab_err+0x130/0x170 mm/slub.c:1026
 list_slab_objects+0x38/0x1a0 mm/slub.c:4596
 free_partial mm/slub.c:4629 [inline]
 __kmem_cache_shutdown+0x132/0x230 mm/slub.c:4661
 shutdown_cache mm/slab_common.c:457 [inline]
 kmem_cache_destroy+0x56/0x160 mm/slab_common.c:497
 shrink_stripes drivers/md/raid5.c:2726 [inline]
 free_conf+0x227/0x4b0 drivers/md/raid5.c:7442
 raid5_run+0x23a5/0x2a00 drivers/md/raid5.c:8150
 level_store+0x1646/0x1a90 drivers/md/md.c:4128
 md_attr_store+0x196/0x380 drivers/md/md.c:5637
 kernfs_fop_write_iter+0x3a4/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2018 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x474/0x9a0 fs/read_write.c:584
 ksys_write+0x151/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f988e79e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f988f61a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f988ea26090 RCX: 00007f988e79e159
RDX: 0000000000000005 RSI: 0000200000000300 RDI: 0000000000000005
RBP: 00007f988e83506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f988ea26128 R14: 00007f988ea26090 R15: 00007ffe0511a358
 </TASK>
BUG raid5-md0 (Not tainted): Objects remaining in raid5-md0 on __kmem_cache_shutdown()
-----------------------------------------------------------------------------

Slab 0xffffea000190c500 objects=13 used=9 fp=0xffff888064316b98 flags=0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
CPU: 0 PID: 14113 Comm: syz.6.2074 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 slab_err+0x13d/0x170 mm/slub.c:1028
 list_slab_objects+0x38/0x1a0 mm/slub.c:4596
 free_partial mm/slub.c:4629 [inline]
 __kmem_cache_shutdown+0x132/0x230 mm/slub.c:4661
 shutdown_cache mm/slab_common.c:457 [inline]
 kmem_cache_destroy+0x56/0x160 mm/slab_common.c:497
 shrink_stripes drivers/md/raid5.c:2726 [inline]
 free_conf+0x227/0x4b0 drivers/md/raid5.c:7442
 raid5_run+0x23a5/0x2a00 drivers/md/raid5.c:8150
 level_store+0x1646/0x1a90 drivers/md/md.c:4128
 md_attr_store+0x196/0x380 drivers/md/md.c:5637
 kernfs_fop_write_iter+0x3a4/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2018 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x474/0x9a0 fs/read_write.c:584
 ksys_write+0x151/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f988e79e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f988f61a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f988ea26090 RCX: 00007f988e79e159
RDX: 0000000000000005 RSI: 0000200000000300 RDI: 0000000000000005
RBP: 00007f988e83506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f988ea26128 R14: 00007f988ea26090 R15: 00007ffe0511a358
 </TASK>
Object 0xffff888064314000 @offset=0
Object 0xffff8880643144d8 @offset=1240
Object 0xffff8880643149b0 @offset=2480
Object 0xffff888064314e88 @offset=3720
Object 0xffff888064315360 @offset=4960
Object 0xffff888064315838 @offset=6200
Object 0xffff888064315d10 @offset=7440
Object 0xffff8880643161e8 @offset=8680
Object 0xffff8880643166c0 @offset=9920
------------[ cut here ]------------
kmem_cache_destroy raid5-md0: Slab cache still has objects when called from shrink_stripes drivers/md/raid5.c:2726 [inline]
kmem_cache_destroy raid5-md0: Slab cache still has objects when called from free_conf+0x227/0x4b0 drivers/md/raid5.c:7442
WARNING: CPU: 0 PID: 14113 at mm/slab_common.c:499 kmem_cache_destroy+0x74/0x160 mm/slab_common.c:498
Modules linked in:
CPU: 0 PID: 14113 Comm: syz.6.2074 Tainted: G    B              syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:kmem_cache_destroy+0x74/0x160 mm/slab_common.c:498
Code: 52 9d 1a 00 48 89 df e8 ea f3 19 00 85 c0 74 33 48 8b 53 60 48 c7 c7 84 49 89 8c 48 c7 c6 31 71 a6 8c 4c 89 f1 e8 7c e5 8b ff <0f> 0b 48 c7 c7 f0 0a 20 8d e8 5e 83 d4 08 5b 41 5e 41 5f 5d e9 63
RSP: 0018:ffffc900042579c0 EFLAGS: 00010246
RAX: 5843c34a25ee3000 RBX: ffff88802f17bc80 RCX: 0000000000080000
RDX: ffffc9000d83d000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 0000000048000000 R08: ffffc900042575c7 R09: 1ffff9200084aeb8
R10: dffffc0000000000 R11: fffff5200084aeb9 R12: ffff88807a02a000
R13: ffff888077330000 R14: ffffffff8777c207 R15: 0000000000000000
FS:  00007f988f61a6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555571213a38 CR3: 000000007b762000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 shrink_stripes drivers/md/raid5.c:2726 [inline]
 free_conf+0x227/0x4b0 drivers/md/raid5.c:7442
 raid5_run+0x23a5/0x2a00 drivers/md/raid5.c:8150
 level_store+0x1646/0x1a90 drivers/md/md.c:4128
 md_attr_store+0x196/0x380 drivers/md/md.c:5637
 kernfs_fop_write_iter+0x3a4/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2018 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x474/0x9a0 fs/read_write.c:584
 ksys_write+0x151/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f988e79e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f988f61a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f988ea26090 RCX: 00007f988e79e159
RDX: 0000000000000005 RSI: 0000200000000300 RDI: 0000000000000005
RBP: 00007f988e83506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f988ea26128 R14: 00007f988ea26090 R15: 00007ffe0511a358
 </TASK>