RBP: 00007fe8824271d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffdf636607f R14: 00007fe882427300 R15: 0000000000022000 ====================================================== WARNING: possible circular locking dependency detected 5.10.215 #1 Not tainted ------------------------------------------------------ syz-executor.4/7346 is trying to acquire lock: ffffffff84f0ce40 (console_owner){-.-.}-{0:0}, at: console_unlock+0x2e1/0xb40 kernel/printk/printk.c:2513 but task is already holding lock: ffff8880175bb158 (&port->lock){-.-.}-{2:2}, at: tty_insert_flip_string_and_push_buffer+0x2b/0x160 drivers/tty/tty_buffer.c:575 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&port->lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x36/0x60 kernel/locking/spinlock.c:159 tty_port_tty_get+0x1f/0x100 drivers/tty/tty_port.c:289 tty_port_default_wakeup+0x11/0x40 drivers/tty/tty_port.c:48 serial8250_tx_chars+0x51f/0xb00 drivers/tty/serial/8250/8250_port.c:1826 serial8250_handle_irq+0x4e4/0x660 drivers/tty/serial/8250/8250_port.c:1922 serial8250_default_handle_irq+0x96/0x210 drivers/tty/serial/8250/8250_port.c:1938 serial8250_interrupt+0xf4/0x1b0 drivers/tty/serial/8250/8250_core.c:127 __handle_irq_event_percpu+0x2ef/0x6d0 kernel/irq/handle.c:156 handle_irq_event_percpu kernel/irq/handle.c:196 [inline] handle_irq_event+0xff/0x280 kernel/irq/handle.c:213 handle_edge_irq+0x249/0xd00 kernel/irq/chip.c:822 asm_call_irq_on_stack+0x12/0x20 __run_irq_on_irqstack arch/x86/include/asm/irq_stack.h:48 [inline] run_irq_on_irqstack_cond arch/x86/include/asm/irq_stack.h:101 [inline] handle_irq arch/x86/kernel/irq.c:230 [inline] __common_interrupt arch/x86/kernel/irq.c:249 [inline] common_interrupt+0xdd/0x1a0 arch/x86/kernel/irq.c:239 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:626 native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline] arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline] default_idle+0xe/0x20 arch/x86/kernel/process.c:706 default_idle_call+0xbf/0x2c0 kernel/sched/idle.c:112 cpuidle_idle_call kernel/sched/idle.c:194 [inline] do_idle+0x3ad/0x520 kernel/sched/idle.c:300 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:396 secondary_startup_64_no_verify+0xbe/0xcb -> #1 (&port_lock_key){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x36/0x60 kernel/locking/spinlock.c:159 serial8250_console_write+0x9f5/0xc60 drivers/tty/serial/8250/8250_port.c:3325 call_console_drivers kernel/printk/printk.c:1917 [inline] console_unlock+0x82a/0xb40 kernel/printk/printk.c:2538 register_console kernel/printk/printk.c:2902 [inline] register_console+0x40c/0x850 kernel/printk/printk.c:2802 univ8250_console_init+0x3a/0x4a drivers/tty/serial/8250/8250_core.c:700 console_init+0x24c/0x356 kernel/printk/printk.c:3012 start_kernel+0x2e6/0x489 init/main.c:979 secondary_startup_64_no_verify+0xbe/0xcb -> #0 (console_owner){-.-.}-{0:0}: check_prev_add kernel/locking/lockdep.c:2988 [inline] check_prevs_add kernel/locking/lockdep.c:3113 [inline] validate_chain kernel/locking/lockdep.c:3729 [inline] __lock_acquire+0x29e7/0x5b00 kernel/locking/lockdep.c:4955 lock_acquire kernel/locking/lockdep.c:5566 [inline] lock_acquire+0x197/0x470 kernel/locking/lockdep.c:5531 console_lock_spinning_enable kernel/printk/printk.c:1763 [inline] console_unlock+0x360/0xb40 kernel/printk/printk.c:2535 vprintk_emit+0x1de/0x4e0 kernel/printk/printk.c:2060 vprintk_func+0x8b/0x140 kernel/printk/printk_safe.c:401 printk+0xba/0xf1 kernel/printk/printk.c:2108 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x47a/0x5a0 lib/fault-inject.c:146 should_failslab+0x5/0x20 mm/slab_common.c:1193 slab_pre_alloc_hook mm/slab.h:515 [inline] slab_alloc_node mm/slub.c:2821 [inline] slab_alloc mm/slub.c:2904 [inline] __kmalloc+0x72/0x390 mm/slub.c:3967 kmalloc include/linux/slab.h:557 [inline] tty_buffer_alloc+0x243/0x2b0 drivers/tty/tty_buffer.c:175 __tty_buffer_request_room+0x156/0x2a0 drivers/tty/tty_buffer.c:274 tty_insert_flip_string_fixed_flag+0x91/0x250 drivers/tty/tty_buffer.c:319 tty_insert_flip_string include/linux/tty_flip.h:36 [inline] tty_insert_flip_string_and_push_buffer+0x3e/0x160 drivers/tty/tty_buffer.c:576 pty_write+0xe6/0x110 drivers/tty/pty.c:119 n_tty_write+0xa86/0xfe0 drivers/tty/n_tty.c:2407 do_tty_write drivers/tty/tty_io.c:1029 [inline] file_tty_write.constprop.0+0x529/0x910 drivers/tty/tty_io.c:1119 call_write_iter include/linux/fs.h:1964 [inline] do_iter_readv_writev+0x476/0x750 fs/read_write.c:740 do_iter_write+0x191/0x670 fs/read_write.c:866 vfs_writev+0x1ae/0x620 fs/read_write.c:939 do_writev+0x139/0x300 fs/read_write.c:982 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xcc other info that might help us debug this: Chain exists of: console_owner --> &port_lock_key --> &port->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&port->lock); lock(&port_lock_key); lock(&port->lock); lock(console_owner); *** DEADLOCK *** 6 locks held by syz-executor.4/7346: #0: ffff888019d45098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x90 drivers/tty/tty_ldisc.c:267 #1: ffff888019d45130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: tty_write_lock drivers/tty/tty_io.c:953 [inline] #1: ffff888019d45130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: do_tty_write drivers/tty/tty_io.c:976 [inline] #1: ffff888019d45130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: file_tty_write.constprop.0+0x29f/0x910 drivers/tty/tty_io.c:1119 #2: ffff888019d452e8 (&tty->termios_rwsem){++++}-{3:3}, at: n_tty_write+0x1bf/0xfe0 drivers/tty/n_tty.c:2367 #3: ffffc900118c5378 (&ldata->output_lock){+.+.}-{3:3}, at: n_tty_write+0xa4d/0xfe0 drivers/tty/n_tty.c:2406 #4: ffff8880175bb158 (&port->lock){-.-.}-{2:2}, at: tty_insert_flip_string_and_push_buffer+0x2b/0x160 drivers/tty/tty_buffer.c:575 #5: ffffffff84fed1c0 (console_lock){+.+.}-{0:0}, at: vprintk_func+0x8b/0x140 kernel/printk/printk_safe.c:401 stack backtrace: CPU: 0 PID: 7346 Comm: syz-executor.4 Not tainted 5.10.215 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:118 check_noncircular+0x263/0x2e0 kernel/locking/lockdep.c:2123 check_prev_add kernel/locking/lockdep.c:2988 [inline] check_prevs_add kernel/locking/lockdep.c:3113 [inline] validate_chain kernel/locking/lockdep.c:3729 [inline] __lock_acquire+0x29e7/0x5b00 kernel/locking/lockdep.c:4955 lock_acquire kernel/locking/lockdep.c:5566 [inline] lock_acquire+0x197/0x470 kernel/locking/lockdep.c:5531 console_lock_spinning_enable kernel/printk/printk.c:1763 [inline] console_unlock+0x360/0xb40 kernel/printk/printk.c:2535 vprintk_emit+0x1de/0x4e0 kernel/printk/printk.c:2060 vprintk_func+0x8b/0x140 kernel/printk/printk_safe.c:401 printk+0xba/0xf1 kernel/printk/printk.c:2108 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x47a/0x5a0 lib/fault-inject.c:146 should_failslab+0x5/0x20 mm/slab_common.c:1193 slab_pre_alloc_hook mm/slab.h:515 [inline] slab_alloc_node mm/slub.c:2821 [inline] slab_alloc mm/slub.c:2904 [inline] __kmalloc+0x72/0x390 mm/slub.c:3967 kmalloc include/linux/slab.h:557 [inline] tty_buffer_alloc+0x243/0x2b0 drivers/tty/tty_buffer.c:175 __tty_buffer_request_room+0x156/0x2a0 drivers/tty/tty_buffer.c:274 tty_insert_flip_string_fixed_flag+0x91/0x250 drivers/tty/tty_buffer.c:319 tty_insert_flip_string include/linux/tty_flip.h:36 [inline] tty_insert_flip_string_and_push_buffer+0x3e/0x160 drivers/tty/tty_buffer.c:576 pty_write+0xe6/0x110 drivers/tty/pty.c:119 n_tty_write+0xa86/0xfe0 drivers/tty/n_tty.c:2407 do_tty_write drivers/tty/tty_io.c:1029 [inline] file_tty_write.constprop.0+0x529/0x910 drivers/tty/tty_io.c:1119 call_write_iter include/linux/fs.h:1964 [inline] do_iter_readv_writev+0x476/0x750 fs/read_write.c:740 do_iter_write+0x191/0x670 fs/read_write.c:866 vfs_writev+0x1ae/0x620 fs/read_write.c:939 do_writev+0x139/0x300 fs/read_write.c:982 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xcc RIP: 0033:0x7fe884eb1b19 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe882427188 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007fe884fc4f60 RCX: 00007fe884eb1b19 RDX: 0000000000000003 RSI: 0000000020000a80 RDI: 0000000000000003 RBP: 00007fe8824271d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffdf636607f R14: 00007fe882427300 R15: 0000000000022000 sr 1:0:0:0: [sr0] tag#0 unaligned transfer print_req_error: 6 callbacks suppressed blk_update_request: I/O error, dev sr0, sector 2096896 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 blk_update_request: I/O error, dev loop4, sector 2096896 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev loop4, logical block 2096896, async page read sr 1:0:0:0: [sr0] tag#0 unaligned transfer blk_update_request: I/O error, dev sr0, sector 2096897 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 blk_update_request: I/O error, dev loop4, sector 2096897 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev loop4, logical block 2096897, async page read sr 1:0:0:0: [sr0] tag#0 unaligned transfer blk_update_request: I/O error, dev sr0, sector 2096898 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 blk_update_request: I/O error, dev loop4, sector 2096898 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev loop4, logical block 2096898, async page read sr 1:0:0:0: [sr0] tag#0 unaligned transfer blk_update_request: I/O error, dev sr0, sector 2096899 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 blk_update_request: I/O error, dev loop4, sector 2096899 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev loop4, logical block 2096899, async page read sr 1:0:0:0: [sr0] tag#0 unaligned transfer blk_update_request: I/O error, dev sr0, sector 2096900 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 sr 1:0:0:0: [sr0] tag#0 unaligned transfer blk_update_request: I/O error, dev sr0, sector 2096901 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 sr 1:0:0:0: [sr0] tag#0 unaligned transfer sr 1:0:0:0: [sr0] tag#0 unaligned transfer Buffer I/O error on dev loop4, logical block 2096900, async page read Buffer I/O error on dev loop4, logical block 2096901, async page read Buffer I/O error on dev loop4, logical block 2096902, async page read Buffer I/O error on dev loop4, logical block 2096903, async page read sr 1:0:0:0: [sr0] tag#0 unaligned transfer Buffer I/O error on dev loop4, logical block 2096896, async page read sr 1:0:0:0: [sr0] tag#0 unaligned transfer Buffer I/O error on dev loop4, logical block 2096897, async page read sr 1:0:0:0: [sr0] tag#0 unaligned transfer sr 1:0:0:0: [sr0] tag#0 unaligned transfer sr 1:0:0:0: [sr0] tag#0 unaligned transfer sr 1:0:0:0: [sr0] tag#0 unaligned transfer sr 1:0:0:0: [sr0] tag#0 unaligned transfer sr 1:0:0:0: [sr0] tag#0 unaligned transfer sr 1:0:0:0: [sr0] tag#0 unaligned transfer sr 1:0:0:0: [sr0] tag#0 unaligned transfer sr 1:0:0:0: [sr0] tag#0 unaligned transfer sr 1:0:0:0: [sr0] tag#0 unaligned transfer sr 1:0:0:0: [sr0] tag#0 unaligned transfer sr 1:0:0:0: [sr0] tag#0 unaligned transfer sr 1:0:0:0: [sr0] tag#0 unaligned transfer sr 1:0:0:0: [sr0] tag#0 unaligned transfer