====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.3.4306/24900 is trying to acquire lock: ffff88807c796c18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1811 [inline] (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3041 but task is already holding lock: ffff888034568a20 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:164 [inline] ffff888034568a20 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6474 [inline] ffff888034568a20 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x3db/0x710 fs/ext4/inode.c:6555 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&ei->xattr_sem){++++}-{4:4}: down_write+0x96/0x200 kernel/locking/rwsem.c:1625 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1805 ext4_do_writepages+0x51e/0x4670 fs/ext4/inode.c:2827 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3042 do_writepages+0x32e/0x550 mm/page-writeback.c:2575 filemap_writeback mm/filemap.c:388 [inline] filemap_flush_range mm/filemap.c:437 [inline] filemap_flush+0x1e1/0x2e0 mm/filemap.c:452 ext4_convert_inline_data+0x18e/0x600 fs/ext4/inline.c:1972 ext4_page_mkwrite+0x247/0x1150 fs/ext4/inode.c:6757 do_page_mkwrite+0x14d/0x310 mm/memory.c:3668 do_shared_fault mm/memory.c:5969 [inline] do_fault mm/memory.c:6031 [inline] do_pte_missing+0x6dc/0x33f0 mm/memory.c:4550 handle_pte_fault mm/memory.c:6411 [inline] __handle_mm_fault mm/memory.c:6549 [inline] handle_mm_fault+0x1bd7/0x3170 mm/memory.c:6718 do_user_addr_fault+0x75b/0x1340 arch/x86/mm/fault.c:1385 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline] copy_to_user_iter lib/iov_iter.c:25 [inline] iterate_ubuf include/linux/iov_iter.h:30 [inline] iterate_and_advance2 include/linux/iov_iter.h:302 [inline] iterate_and_advance include/linux/iov_iter.h:330 [inline] _copy_to_iter+0x250/0x17d0 lib/iov_iter.c:197 copy_to_iter include/linux/uio.h:220 [inline] get_random_bytes_user+0x1cf/0x3d0 drivers/char/random.c:462 __do_sys_getrandom drivers/char/random.c:1406 [inline] __se_sys_getrandom drivers/char/random.c:1380 [inline] __x64_sys_getrandom+0x17a/0x270 drivers/char/random.c:1380 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&sbi->s_writepages_rwsem){++++}-{0:0}: 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+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 percpu_down_read_internal+0x48/0x1c0 include/linux/percpu-rwsem.h:53 percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ext4_writepages_down_read fs/ext4/ext4.h:1811 [inline] ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3041 do_writepages+0x32e/0x550 mm/page-writeback.c:2575 __writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1764 writeback_single_inode+0x4ac/0xdc0 fs/fs-writeback.c:1883 write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2974 iput_final fs/inode.c:1950 [inline] iput+0x8c1/0xe80 fs/inode.c:2009 ext4_xattr_block_set+0x1fd4/0x2ad0 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+0x12cf/0x1ea0 fs/ext4/xattr.c:2834 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6434 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6477 [inline] __ext4_mark_inode_dirty+0x45c/0x710 fs/ext4/inode.c:6555 ext4_evict_inode+0x986/0x10e0 fs/ext4/inode.c:267 evict+0x61e/0xb10 fs/inode.c:841 ext4_orphan_cleanup+0xc38/0x1470 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5701 [inline] ext4_fill_super+0x5a19/0x6330 fs/ext4/super.c:5824 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3834 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4360 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 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 ---- ---- lock(&ei->xattr_sem); lock(&sbi->s_writepages_rwsem); lock(&ei->xattr_sem); rlock(&sbi->s_writepages_rwsem); *** DEADLOCK *** 3 locks held by syz.3.4306/24900: #0: ffff88803f5900d8 (&type->s_umount_key#29/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:345 #1: ffff88803f590600 (sb_internal){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] #1: ffff88803f590600 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline] #1: ffff88803f590600 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs/super.h:177 [inline] #1: ffff88803f590600 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x426/0x10e0 fs/ext4/inode.c:228 #2: ffff888034568a20 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:164 [inline] #2: ffff888034568a20 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6474 [inline] #2: ffff888034568a20 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x3db/0x710 fs/ext4/inode.c:6555 stack backtrace: CPU: 0 UID: 0 PID: 24900 Comm: syz.3.4306 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 percpu_down_read_internal+0x48/0x1c0 include/linux/percpu-rwsem.h:53 percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ext4_writepages_down_read fs/ext4/ext4.h:1811 [inline] ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3041 do_writepages+0x32e/0x550 mm/page-writeback.c:2575 __writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1764 writeback_single_inode+0x4ac/0xdc0 fs/fs-writeback.c:1883 write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2974 iput_final fs/inode.c:1950 [inline] iput+0x8c1/0xe80 fs/inode.c:2009 ext4_xattr_block_set+0x1fd4/0x2ad0 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+0x12cf/0x1ea0 fs/ext4/xattr.c:2834 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6434 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6477 [inline] __ext4_mark_inode_dirty+0x45c/0x710 fs/ext4/inode.c:6555 ext4_evict_inode+0x986/0x10e0 fs/ext4/inode.c:267 evict+0x61e/0xb10 fs/inode.c:841 ext4_orphan_cleanup+0xc38/0x1470 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5701 [inline] ext4_fill_super+0x5a19/0x6330 fs/ext4/super.c:5824 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3834 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4360 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fed8e79e04a 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:00007fed8f6b6e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fed8f6b6ee0 RCX: 00007fed8e79e04a RDX: 0000200000000180 RSI: 0000200000000000 RDI: 00007fed8f6b6ea0 RBP: 0000200000000180 R08: 00007fed8f6b6ee0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000000 R13: 00007fed8f6b6ea0 R14: 000000000000047a R15: 000000000000002c EXT4-fs error (device loop3): ext4_xattr_inode_iget:441: inode #11: comm syz.3.4306: iget: bad extra_isize 90 (inode size 256) loop3: lost file I/O error report for ino 11 type 5 pos 0x0 len 0x0 error -117 EXT4-fs (loop3): Remounting filesystem read-only EXT4-fs warning (device loop3): ext4_evict_inode:270: couldn't mark inode dirty (err -30) EXT4-fs (loop3): 1 orphan inode deleted EXT4-fs (loop3): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none. raw-gadget.2 gadget.3: fail, usb_ep_enable returned -22