============================= WARNING: suspicious RCU usage syzkaller #0 Tainted: G L ----------------------------- fs/btrfs/volumes.h:872 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by syz.2.484/7722: #0: ffff8880586fa0e0 (&type->s_umount_key#52/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:345 stack backtrace: CPU: 0 UID: 0 PID: 7722 Comm: syz.2.484 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x13f/0x1d0 kernel/locking/lockdep.c:6876 btrfs_dev_name+0x128/0x130 fs/btrfs/volumes.h:872 btrfs_repair_io_failure+0x4f8/0x6a0 fs/btrfs/bio.c:989 btrfs_repair_eb_io_failure fs/btrfs/disk-io.c:198 [inline] btrfs_read_extent_buffer+0xb84/0xcd0 fs/btrfs/disk-io.c:245 read_tree_block fs/btrfs/disk-io.c:592 [inline] load_super_root+0x162/0x350 fs/btrfs/disk-io.c:2619 load_important_roots fs/btrfs/disk-io.c:2641 [inline] init_tree_roots+0x98e/0x2240 fs/btrfs/disk-io.c:2694 open_ctree+0x1960/0x2e40 fs/btrfs/disk-io.c:3489 btrfs_fill_super+0x187/0x2e0 fs/btrfs/super.c:981 btrfs_get_tree_super fs/btrfs/super.c:1944 [inline] btrfs_get_tree_subvol fs/btrfs/super.c:2087 [inline] btrfs_get_tree+0xe77/0x1370 fs/btrfs/super.c:2121 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3763 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3839 do_mount fs/namespace.c:4172 [inline] __do_sys_mount fs/namespace.c:4361 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4338 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f58f8d9da0a Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f58f9c7ce58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f58f9c7cee0 RCX: 00007f58f8d9da0a RDX: 00002000000002c0 RSI: 0000200000000680 RDI: 00007f58f9c7cea0 RBP: 00002000000002c0 R08: 00007f58f9c7cee0 R09: 0000000001a001d8 R10: 0000000001a001d8 R11: 0000000000000246 R12: 0000200000000680 R13: 00007f58f9c7cea0 R14: 0000000000022233 R15: 0000200000000040 BTRFS info (device loop2): read error corrected: ino 0 off 30654464 (dev /dev/loop2 sector 76256) BTRFS info (device loop2): deleted orphan free space tree entries BTRFS info (device loop2): checking UUID tree BTRFS info (device loop2): enabling ssd optimizations BTRFS info (device loop2): using spread ssd allocation scheme BTRFS info (device loop2): turning on async discard BTRFS info (device loop2): enabling free space tree