====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.301/6700 is trying to acquire lock: ffff888063015f78 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ffff888063015f78 (&ei->xattr_sem){++++}-{4:4}, at: ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1805 but task is already holding lock: ffff88804ec4ccd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ffff88804ec4ccd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1876 [inline] ffff88804ec4ccd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3042 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sbi->s_writepages_rwsem){++++}-{0:0}: percpu_down_read_internal+0x48/0x1d0 include/linux/percpu-rwsem.h:53 percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ext4_writepages_down_read fs/ext4/ext4.h:1876 [inline] ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3042 do_writepages+0x338/0x560 mm/page-writeback.c:2571 __writeback_single_inode+0x12e/0xf90 fs/fs-writeback.c:1787 writeback_single_inode+0x4dd/0xe10 fs/fs-writeback.c:1906 write_inode_now+0x1c2/0x290 fs/fs-writeback.c:3060 iput_final fs/inode.c:2009 [inline] iput+0x98b/0xf00 fs/inode.c:2068 ext4_xattr_block_set+0x1b0c/0x2a80 fs/ext4/xattr.c:2206 ext4_xattr_move_to_block fs/ext4/xattr.c:2671 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2746 [inline] ext4_expand_extra_isize_ea+0x1342/0x1e70 fs/ext4/xattr.c:2834 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6486 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6529 [inline] __ext4_mark_inode_dirty+0x455/0x700 fs/ext4/inode.c:6607 ext4_evict_inode+0x976/0x10c0 fs/ext4/inode.c:267 evict+0x624/0xb50 fs/inode.c:825 ext4_orphan_cleanup+0xc7a/0x14c0 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5705 [inline] ext4_fill_super+0x5cc0/0x65d0 fs/ext4/super.c:5828 get_tree_bdev_flags+0x430/0x4f0 fs/super.c:1634 vfs_get_tree+0x92/0x2a0 fs/super.c:1694 fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3765 [inline] do_new_mount+0x319/0xdc0 fs/namespace.c:3841 do_mount fs/namespace.c:4174 [inline] __do_sys_mount fs/namespace.c:4390 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4367 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&ei->xattr_sem){++++}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x1520/0x2ce0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 down_write+0x3a/0x50 kernel/locking/rwsem.c:1631 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1805 ext4_do_writepages+0x576/0x47a0 fs/ext4/inode.c:2828 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3043 do_writepages+0x338/0x560 mm/page-writeback.c:2571 filemap_writeback mm/filemap.c:387 [inline] filemap_fdatawrite_range mm/filemap.c:412 [inline] file_write_and_wait_range+0x374/0x440 mm/filemap.c:786 mmb_fsync_noflush+0x76/0x1d0 fs/buffer.c:652 ext4_fsync_nojournal fs/ext4/fsync.c:92 [inline] ext4_sync_file+0x423/0xd10 fs/ext4/fsync.c:160 generic_write_sync include/linux/fs.h:2661 [inline] ext4_buffered_write_iter+0x2ca/0x370 fs/ext4/file.c:322 ext4_file_write_iter+0x94b/0x1c90 fs/ext4/file.c:-1 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61e/0xbb0 fs/read_write.c:687 ksys_write+0x156/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(&sbi->s_writepages_rwsem); lock(&ei->xattr_sem); lock(&sbi->s_writepages_rwsem); lock(&ei->xattr_sem); *** DEADLOCK *** 3 locks held by syz.0.301/6700: #0: ffff88803b3caf28 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1259 #1: ffff88803601e500 (sb_writers#4){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2728 [inline] #1: ffff88803601e500 (sb_writers#4){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #2: ffff88804ec4ccd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #2: ffff88804ec4ccd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1876 [inline] #2: ffff88804ec4ccd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3042 stack backtrace: CPU: 1 UID: 0 PID: 6700 Comm: syz.0.301 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x1520/0x2ce0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 down_write+0x3a/0x50 kernel/locking/rwsem.c:1631 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1805 ext4_do_writepages+0x576/0x47a0 fs/ext4/inode.c:2828 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3043 do_writepages+0x338/0x560 mm/page-writeback.c:2571 filemap_writeback mm/filemap.c:387 [inline] filemap_fdatawrite_range mm/filemap.c:412 [inline] file_write_and_wait_range+0x374/0x440 mm/filemap.c:786 mmb_fsync_noflush+0x76/0x1d0 fs/buffer.c:652 ext4_fsync_nojournal fs/ext4/fsync.c:92 [inline] ext4_sync_file+0x423/0xd10 fs/ext4/fsync.c:160 generic_write_sync include/linux/fs.h:2661 [inline] ext4_buffered_write_iter+0x2ca/0x370 fs/ext4/file.c:322 ext4_file_write_iter+0x94b/0x1c90 fs/ext4/file.c:-1 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61e/0xbb0 fs/read_write.c:687 ksys_write+0x156/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2ea5cbde59 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:00007f2ea3f16028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f2ea5f45fa0 RCX: 00007f2ea5cbde59 RDX: 0000000000001006 RSI: 0000200000001440 RDI: 0000000000000004 RBP: 00007f2ea5d53e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2ea5f46038 R14: 00007f2ea5f45fa0 R15: 00007ffd91009fd8 EXT4-fs error (device loop0): ext4_mb_generate_buddy:1317: group 0, block bitmap and bg descriptor inconsistent: 25 vs 281 free clusters EXT4-fs (loop0): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 3 with error 28 EXT4-fs (loop0): This should not happen!! Data will be lost EXT4-fs (loop0): Total free blocks count 0 EXT4-fs (loop0): Free/Dirty block details EXT4-fs (loop0): free_blocks=4096 EXT4-fs (loop0): dirty_blocks=16 EXT4-fs (loop0): Block reservation details EXT4-fs (loop0): i_reserved_data_blocks=1