====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.1.1876/12289 is trying to acquire lock: ffff88804dde46c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline] ffff88804dde46c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1884 but task is already holding lock: ffff88807b43abd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1767 [inline] ffff88807b43abd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x170/0x2f0 fs/ext4/inode.c:2806 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+0x44/0x1a0 include/linux/percpu-rwsem.h:51 ext4_writepages_down_read fs/ext4/ext4.h:1767 [inline] ext4_writepages+0x170/0x2f0 fs/ext4/inode.c:2806 do_writepages+0x3a2/0x600 mm/page-writeback.c:2575 __writeback_single_inode+0x153/0xee0 fs/fs-writeback.c:1635 writeback_single_inode+0x211/0x720 fs/fs-writeback.c:1756 write_inode_now+0x161/0x1e0 fs/fs-writeback.c:2802 iput_final fs/inode.c:1807 [inline] iput+0x5b2/0x920 fs/inode.c:1846 ext4_xattr_block_set+0x273a/0x32a0 fs/ext4/xattr.c:2211 ext4_xattr_move_to_block fs/ext4/xattr.c:2679 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2754 [inline] ext4_expand_extra_isize_ea+0x10ea/0x19e0 fs/ext4/xattr.c:2846 __ext4_expand_extra_isize+0x306/0x400 fs/ext4/inode.c:5967 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6010 [inline] __ext4_mark_inode_dirty+0x45d/0x6e0 fs/ext4/inode.c:6088 ext4_evict_inode+0x7ed/0xea0 fs/ext4/inode.c:252 evict+0x486/0x870 fs/inode.c:705 ext4_orphan_cleanup+0xbd4/0x1400 fs/ext4/orphan.c:470 __ext4_fill_super fs/ext4/super.c:5601 [inline] ext4_fill_super+0x5de4/0x66c0 fs/ext4/super.c:5724 get_tree_bdev+0x3e4/0x510 fs/super.c:1591 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24b/0xa40 fs/namespace.c:3386 do_mount fs/namespace.c:3726 [inline] __do_sys_mount fs/namespace.c:3935 [inline] __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3912 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&ei->xattr_sem){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573 ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1884 ext4_do_writepages+0x4c2/0x38d0 fs/ext4/inode.c:2604 ext4_writepages+0x1a8/0x2f0 fs/ext4/inode.c:2807 do_writepages+0x3a2/0x600 mm/page-writeback.c:2575 filemap_fdatawrite_wbc+0x122/0x180 mm/filemap.c:390 __filemap_fdatawrite_range mm/filemap.c:423 [inline] __filemap_fdatawrite mm/filemap.c:429 [inline] filemap_flush+0xc5/0x120 mm/filemap.c:456 ext4_release_file+0x82/0x310 fs/ext4/file.c:169 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1ce/0x250 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x90b/0x23c0 kernel/exit.c:883 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 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 *** 1 lock held by syz.1.1876/12289: #0: ffff88807b43abd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1767 [inline] #0: ffff88807b43abd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x170/0x2f0 fs/ext4/inode.c:2806 stack backtrace: CPU: 1 PID: 12289 Comm: syz.1.1876 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 check_noncircular+0x2bd/0x3c0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573 ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1884 ext4_do_writepages+0x4c2/0x38d0 fs/ext4/inode.c:2604 ext4_writepages+0x1a8/0x2f0 fs/ext4/inode.c:2807 do_writepages+0x3a2/0x600 mm/page-writeback.c:2575 filemap_fdatawrite_wbc+0x122/0x180 mm/filemap.c:390 __filemap_fdatawrite_range mm/filemap.c:423 [inline] __filemap_fdatawrite mm/filemap.c:429 [inline] filemap_flush+0xc5/0x120 mm/filemap.c:456 ext4_release_file+0x82/0x310 fs/ext4/file.c:169 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1ce/0x250 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x90b/0x23c0 kernel/exit.c:883 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f23ec78f749 Code: Unable to access opcode bytes at 0x7f23ec78f71f. RSP: 002b:00007f23ed676038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: 0000200000000000 RBX: 00007f23ec9e6180 RCX: 00007f23ec78f749 RDX: 000000000000000a RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007f23ec813f91 R08: 0000000000000006 R09: 0000000000000000 R10: 0000000000028011 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f23ec9e6218 R14: 00007f23ec9e6180 R15: 00007ffcbe548938 syz.1.1876: attempt to access beyond end of device loop1: rw=1, sector=7212754380, nr_sectors = 4 limit=2048 EXT4-fs warning (device loop1): ext4_end_bio:357: I/O error 10 writing to inode 15 starting block 1803188595) Buffer I/O error on device loop1, logical block 1803188595 EXT4-fs error (device loop1) in ext4_reserve_inode_write:5916: Out of memory EXT4-fs error (device loop1): mpage_map_and_submit_extent:2315: inode #15: comm syz.1.1876: mark_inode_dirty error EXT4-fs error (device loop1): mpage_map_and_submit_extent:2319: comm syz.1.1876: Failed to mark inode 15 dirty syz.1.1876: attempt to access beyond end of device loop1: rw=1, sector=6806417796, nr_sectors = 4 limit=2048 EXT4-fs warning (device loop1): ext4_end_bio:357: I/O error 10 writing to inode 15 starting block 1701604449) Buffer I/O error on device loop1, logical block 1701604449