syzbot

REISERFS warning (device loop0): sh-2029: %s: bitmap block (#%u) reading failed reiserfs_read_bitmap_block: reiserfs_read_bitmap_block
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.17/4503 is trying to acquire lock:
ffff0000ea2c0980 (&type->i_mutex_dir_key#8/3){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline]
ffff0000ea2c0980 (&type->i_mutex_dir_key#8/3){+.+.}-{3:3}, at: open_xa_root fs/reiserfs/xattr.c:127 [inline]
ffff0000ea2c0980 (&type->i_mutex_dir_key#8/3){+.+.}-{3:3}, at: open_xa_dir+0x124/0x5f0 fs/reiserfs/xattr.c:152

but task is already holding lock:
ffff0000df661090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock_nested+0x68/0xd8 fs/reiserfs/lock.c:78

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&sbi->lock){+.+.}-{3:3}:
       __mutex_lock_common+0x190/0x1f60 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
       reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27
       reiserfs_mkdir+0x294/0x7bc fs/reiserfs/namei.c:831
       xattr_mkdir fs/reiserfs/xattr.c:76 [inline]
       open_xa_root fs/reiserfs/xattr.c:136 [inline]
       open_xa_dir+0x290/0x5f0 fs/reiserfs/xattr.c:152
       xattr_lookup+0x3c/0x268 fs/reiserfs/xattr.c:395
       reiserfs_xattr_set_handle+0xe0/0xdac fs/reiserfs/xattr.c:533
       __reiserfs_set_acl+0x428/0x5b0 fs/reiserfs/xattr_acl.c:276
       reiserfs_set_acl+0x3e8/0x590 fs/reiserfs/xattr_acl.c:50
       set_posix_acl fs/posix_acl.c:1160 [inline]
       posix_acl_xattr_set+0x2f8/0x394 fs/posix_acl.c:1189
       __vfs_setxattr+0x384/0x3a0 fs/xattr.c:182
       __vfs_setxattr_noperm+0x120/0x564 fs/xattr.c:216
       __vfs_setxattr_locked+0x1ec/0x218 fs/xattr.c:277
       vfs_setxattr+0x158/0x2ac fs/xattr.c:309
       do_setxattr fs/xattr.c:594 [inline]
       setxattr+0x258/0x2d8 fs/xattr.c:617
       path_setxattr+0x130/0x260 fs/xattr.c:636
       __do_sys_lsetxattr fs/xattr.c:659 [inline]
       __se_sys_lsetxattr fs/xattr.c:655 [inline]
       __arm64_sys_lsetxattr+0xbc/0xd8 fs/xattr.c:655
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
       do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204
       el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

-> #0 (&type->i_mutex_dir_key#8/3){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain kernel/locking/lockdep.c:3825 [inline]
       __lock_acquire+0x2880/0x6800 kernel/locking/lockdep.c:5049
       lock_acquire+0x20c/0x63c kernel/locking/lockdep.c:5662
       down_write_nested+0x64/0x94 kernel/locking/rwsem.c:1689
       inode_lock_nested include/linux/fs.h:793 [inline]
       open_xa_root fs/reiserfs/xattr.c:127 [inline]
       open_xa_dir+0x124/0x5f0 fs/reiserfs/xattr.c:152
       reiserfs_for_each_xattr+0x18c/0x6d8 fs/reiserfs/xattr.c:252
       reiserfs_delete_xattrs+0x2c/0xa4 fs/reiserfs/xattr.c:364
       reiserfs_evict_inode+0x1f0/0x408 fs/reiserfs/inode.c:53
       evict+0x3e0/0x828 fs/inode.c:705
       iput_final fs/inode.c:1834 [inline]
       iput+0x754/0x7e4 fs/inode.c:1860
       reiserfs_new_inode+0xab0/0x13ac fs/reiserfs/inode.c:2156
       reiserfs_mkdir+0x4dc/0x7bc fs/reiserfs/namei.c:845
       vfs_mkdir+0x314/0x4d4 fs/namei.c:4114
       do_mkdirat+0x1b8/0x3ec fs/namei.c:4139
       __do_sys_mkdirat fs/namei.c:4154 [inline]
       __se_sys_mkdirat fs/namei.c:4152 [inline]
       __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4152
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
       do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204
       el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sbi->lock);
                               lock(&type->i_mutex_dir_key#8/3);
                               lock(&sbi->lock);
  lock(&type->i_mutex_dir_key#8/3);

 *** DEADLOCK ***

3 locks held by syz.0.17/4503:
 #0: ffff0000d367e460 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:402
 #1: ffff0000ea2c1020 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline]
 #1: ffff0000ea2c1020 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: filename_create+0x1b0/0x3a8 fs/namei.c:3884
 #2: ffff0000df661090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock_nested+0x68/0xd8 fs/reiserfs/lock.c:78

stack backtrace:
CPU: 1 PID: 4503 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call trace:
 dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106
 dump_stack+0x1c/0x5c lib/dump_stack.c:113
 print_circular_bug+0x148/0x1b0 kernel/locking/lockdep.c:2048
 check_noncircular+0x264/0x2f8 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain kernel/locking/lockdep.c:3825 [inline]
 __lock_acquire+0x2880/0x6800 kernel/locking/lockdep.c:5049
 lock_acquire+0x20c/0x63c kernel/locking/lockdep.c:5662
 down_write_nested+0x64/0x94 kernel/locking/rwsem.c:1689
 inode_lock_nested include/linux/fs.h:793 [inline]
 open_xa_root fs/reiserfs/xattr.c:127 [inline]
 open_xa_dir+0x124/0x5f0 fs/reiserfs/xattr.c:152
 reiserfs_for_each_xattr+0x18c/0x6d8 fs/reiserfs/xattr.c:252
 reiserfs_delete_xattrs+0x2c/0xa4 fs/reiserfs/xattr.c:364
 reiserfs_evict_inode+0x1f0/0x408 fs/reiserfs/inode.c:53
 evict+0x3e0/0x828 fs/inode.c:705
 iput_final fs/inode.c:1834 [inline]
 iput+0x754/0x7e4 fs/inode.c:1860
 reiserfs_new_inode+0xab0/0x13ac fs/reiserfs/inode.c:2156
 reiserfs_mkdir+0x4dc/0x7bc fs/reiserfs/namei.c:845
 vfs_mkdir+0x314/0x4d4 fs/namei.c:4114
 do_mkdirat+0x1b8/0x3ec fs/namei.c:4139
 __do_sys_mkdirat fs/namei.c:4154 [inline]
 __se_sys_mkdirat fs/namei.c:4152 [inline]
 __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4152
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585