loop4: detected capacity change from 0 to 32768 BTRFS: device fsid c9fe44da-de57-406a-8241-57ec7d4412cf devid 1 transid 8 /dev/loop4 scanned by syz.4.583 (7125) ====================================================== WARNING: possible circular locking dependency detected 5.15.178-syzkaller #0 Not tainted ------------------------------------------------------ syz.4.583/7125 is trying to acquire lock: ffff888078066368 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xae/0x1300 kernel/sched/core.c:4027 but task is already holding lock: ffffffff8c9fc538 ((console_sem).lock){-.-.}-{2:2}, at: up+0x19/0x90 kernel/locking/semaphore.c:186 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 ((console_sem).lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:138 __down_trylock_console_sem+0x105/0x250 kernel/printk/printk.c:239 console_trylock kernel/printk/printk.c:2575 [inline] console_trylock_spinning+0x8a/0x3f0 kernel/printk/printk.c:1867 vprintk_emit+0xa6/0x150 kernel/printk/printk.c:2273 _printk+0xd1/0x120 kernel/printk/printk.c:2299 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x36c/0x4c0 lib/fault-inject.c:146 strncpy_from_user+0x32/0x370 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x6c/0x130 mm/maccess.c:295 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:194 [inline] ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:300 [inline] bpf_probe_read_compat_str+0xe4/0x180 kernel/trace/bpf_trace.c:296 0xffffffffa0034fc5 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline] bpf_trace_run3+0x1d1/0x380 kernel/trace/bpf_trace.c:1916 __traceiter_sched_switch+0x7d/0xb0 include/trace/events/sched.h:220 trace_sched_switch include/trace/events/sched.h:220 [inline] __schedule+0x1e8d/0x45b0 kernel/sched/core.c:6370 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 exit_to_user_mode_loop+0x44/0x130 kernel/entry/common.c:169 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681 -> #1 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:368 raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 raw_spin_rq_lock kernel/sched/sched.h:1326 [inline] rq_lock kernel/sched/sched.h:1621 [inline] task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11488 sched_cgroup_fork+0x2d3/0x330 kernel/sched/core.c:4463 copy_process+0x224a/0x3ef0 kernel/fork.c:2319 kernel_clone+0x210/0x960 kernel/fork.c:2603 kernel_thread+0x168/0x1e0 kernel/fork.c:2655 rest_init+0x21/0x330 init/main.c:706 start_kernel+0x48c/0x540 init/main.c:1140 secondary_startup_64_no_verify+0xb1/0xbb -> #0 (&p->pi_lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 try_to_wake_up+0xae/0x1300 kernel/sched/core.c:4027 up+0x6e/0x90 kernel/locking/semaphore.c:190 __up_console_sem+0x11a/0x1e0 kernel/printk/printk.c:256 console_unlock+0x1145/0x12b0 kernel/printk/printk.c:2760 vprintk_emit+0xbf/0x150 kernel/printk/printk.c:2274 _printk+0xd1/0x120 kernel/printk/printk.c:2299 device_list_add+0x13f8/0x2240 btrfs_scan_one_device+0x436/0x690 fs/btrfs/volumes.c:1488 btrfs_mount_root+0x4b4/0x930 fs/btrfs/super.c:1716 legacy_get_tree+0xeb/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 fc_mount fs/namespace.c:1000 [inline] vfs_kern_mount+0xb8/0x150 fs/namespace.c:1030 btrfs_mount+0x395/0xb40 fs/btrfs/super.c:1812 legacy_get_tree+0xeb/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x2ba/0xb40 fs/namespace.c:3012 do_mount fs/namespace.c:3355 [inline] __do_sys_mount fs/namespace.c:3563 [inline] __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3540 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Chain exists of: &p->pi_lock --> &rq->__lock --> (console_sem).lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((console_sem).lock); lock(&rq->__lock); lock((console_sem).lock); lock(&p->pi_lock); *** DEADLOCK *** 3 locks held by syz.4.583/7125: #0: ffffffff8d0119c8 (uuid_mutex){+.+.}-{3:3}, at: btrfs_mount_root+0x27b/0x930 fs/btrfs/super.c:1709 #1: ffff88805d3ca0e0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: device_list_add+0xe2a/0x2240 fs/btrfs/volumes.c:887 #2: ffffffff8c9fc538 ((console_sem).lock){-.-.}-{2:2}, at: up+0x19/0x90 kernel/locking/semaphore.c:186 stack backtrace: CPU: 0 PID: 7125 Comm: syz.4.583 Not tainted 5.15.178-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 try_to_wake_up+0xae/0x1300 kernel/sched/core.c:4027 up+0x6e/0x90 kernel/locking/semaphore.c:190 __up_console_sem+0x11a/0x1e0 kernel/printk/printk.c:256 console_unlock+0x1145/0x12b0 kernel/printk/printk.c:2760 vprintk_emit+0xbf/0x150 kernel/printk/printk.c:2274 _printk+0xd1/0x120 kernel/printk/printk.c:2299 device_list_add+0x13f8/0x2240 btrfs_scan_one_device+0x436/0x690 fs/btrfs/volumes.c:1488 btrfs_mount_root+0x4b4/0x930 fs/btrfs/super.c:1716 legacy_get_tree+0xeb/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 fc_mount fs/namespace.c:1000 [inline] vfs_kern_mount+0xb8/0x150 fs/namespace.c:1030 btrfs_mount+0x395/0xb40 fs/btrfs/super.c:1812 legacy_get_tree+0xeb/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x2ba/0xb40 fs/namespace.c:3012 do_mount fs/namespace.c:3355 [inline] __do_sys_mount fs/namespace.c:3563 [inline] __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3540 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f998dcfb58a Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f998bb62e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f998bb62ef0 RCX: 00007f998dcfb58a RDX: 0000400000005100 RSI: 0000400000005140 RDI: 00007f998bb62eb0 RBP: 0000400000005100 R08: 00007f998bb62ef0 R09: 0000000000000012 R10: 0000000000000012 R11: 0000000000000246 R12: 0000400000005140 R13: 00007f998bb62eb0 R14: 000000000000510c R15: 0000400000000140 BTRFS info (device loop4): using crc32c (crc32c-intel) checksum algorithm BTRFS info (device loop4): setting incompat feature flag for COMPRESS_ZSTD (0x10) BTRFS info (device loop4): use zstd compression, level 3 BTRFS info (device loop4): using free space tree BTRFS info (device loop4): has skinny extents BTRFS info (device loop4): enabling ssd optimizations