EXT4-fs (loop4): Warning: mounting with an experimental mount option 'dioread_nolock' for blocksize < PAGE_SIZE ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.4.518/5560 is trying to acquire lock: ffff88801bec6c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x20f/0x2df0 fs/ext4/inode.c:2691 but task is already holding lock: ffff88801bec4650 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1811 [inline] ffff88801bec4650 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1928 [inline] ffff88801bec4650 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x44a/0x1090 fs/ext4/inode.c:245 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (sb_internal){.+.+}-{0:0}: percpu_down_read+0x46/0x1b0 include/linux/percpu-rwsem.h:51 __sb_start_write include/linux/fs.h:1811 [inline] sb_start_intwrite include/linux/fs.h:1928 [inline] ext4_evict_inode+0x44a/0x1090 fs/ext4/inode.c:245 evict+0x4c9/0x8d0 fs/inode.c:647 ext4_ext_migrate+0xc0c/0xe60 fs/ext4/migrate.c:588 __ext4_ioctl fs/ext4/ioctl.c:1031 [inline] ext4_ioctl+0x1a84/0x3870 fs/ext4/ioctl.c:1285 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&sbi->s_writepages_rwsem){++++}-{0:0}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 percpu_down_read+0x46/0x1b0 include/linux/percpu-rwsem.h:51 ext4_writepages+0x20f/0x2df0 fs/ext4/inode.c:2691 do_writepages+0x476/0x6e0 mm/page-writeback.c:2386 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657 writeback_single_inode+0x3cb/0x8e0 fs/fs-writeback.c:1770 write_inode_now+0x23b/0x2c0 fs/fs-writeback.c:2817 iput_final fs/inode.c:1756 [inline] iput+0x5ab/0x8a0 fs/inode.c:1795 ext4_xattr_set_entry+0x34f4/0x3ea0 fs/ext4/xattr.c:1825 ext4_xattr_block_set+0x979/0x2d20 fs/ext4/xattr.c:1993 ext4_xattr_move_to_block fs/ext4/xattr.c:2618 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2693 [inline] ext4_expand_extra_isize_ea+0xf3f/0x19b0 fs/ext4/xattr.c:2781 __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:5924 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5967 [inline] __ext4_mark_inode_dirty+0x469/0x700 fs/ext4/inode.c:6045 ext4_evict_inode+0xa8d/0x1090 fs/ext4/inode.c:284 evict+0x4c9/0x8d0 fs/inode.c:647 ext4_orphan_cleanup+0xad2/0x1320 fs/ext4/orphan.c:472 ext4_fill_super+0x8d6e/0x94f0 fs/ext4/super.c:5006 mount_bdev+0x287/0x3c0 fs/super.c:1400 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3034 do_mount fs/namespace.c:3377 [inline] __do_sys_mount fs/namespace.c:3585 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_internal); lock(&sbi->s_writepages_rwsem); lock(sb_internal); lock(&sbi->s_writepages_rwsem); *** DEADLOCK *** 3 locks held by syz.4.518/5560: #0: ffff88801bec40e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 #1: ffff88801bec4650 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1811 [inline] #1: ffff88801bec4650 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1928 [inline] #1: ffff88801bec4650 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x44a/0x1090 fs/ext4/inode.c:245 #2: ffff888061abd088 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:165 [inline] #2: ffff888061abd088 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:5964 [inline] #2: ffff888061abd088 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x3e8/0x700 fs/ext4/inode.c:6045 stack backtrace: CPU: 1 PID: 5560 Comm: syz.4.518 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 percpu_down_read+0x46/0x1b0 include/linux/percpu-rwsem.h:51 ext4_writepages+0x20f/0x2df0 fs/ext4/inode.c:2691 do_writepages+0x476/0x6e0 mm/page-writeback.c:2386 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657 writeback_single_inode+0x3cb/0x8e0 fs/fs-writeback.c:1770 write_inode_now+0x23b/0x2c0 fs/fs-writeback.c:2817 iput_final fs/inode.c:1756 [inline] iput+0x5ab/0x8a0 fs/inode.c:1795 ext4_xattr_set_entry+0x34f4/0x3ea0 fs/ext4/xattr.c:1825 ext4_xattr_block_set+0x979/0x2d20 fs/ext4/xattr.c:1993 ext4_xattr_move_to_block fs/ext4/xattr.c:2618 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2693 [inline] ext4_expand_extra_isize_ea+0xf3f/0x19b0 fs/ext4/xattr.c:2781 __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:5924 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5967 [inline] __ext4_mark_inode_dirty+0x469/0x700 fs/ext4/inode.c:6045 ext4_evict_inode+0xa8d/0x1090 fs/ext4/inode.c:284 evict+0x4c9/0x8d0 fs/inode.c:647 ext4_orphan_cleanup+0xad2/0x1320 fs/ext4/orphan.c:472 ext4_fill_super+0x8d6e/0x94f0 fs/ext4/super.c:5006 mount_bdev+0x287/0x3c0 fs/super.c:1400 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3034 do_mount fs/namespace.c:3377 [inline] __do_sys_mount fs/namespace.c:3585 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f8b8609204a 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:00007f8b842e9e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f8b842e9ee0 RCX: 00007f8b8609204a RDX: 0000200000000180 RSI: 0000200000000000 RDI: 00007f8b842e9ea0 RBP: 0000200000000180 R08: 00007f8b842e9ee0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000000 R13: 00007f8b842e9ea0 R14: 000000000000047a R15: 000000000000002c EXT4-fs error (device loop4): ext4_xattr_inode_iget:401: inode #18: comm syz.4.518: iget: bad extra_isize 58 (inode size 256) EXT4-fs (loop4): Remounting filesystem read-only EXT4-fs error (device loop4): ext4_xattr_inode_iget:406: comm syz.4.518: error while reading EA inode 18 err=-117 EXT4-fs (loop4): Remounting filesystem read-only EXT4-fs error (device loop4): ext4_xattr_inode_iget:401: inode #11: comm syz.4.518: iget: bad extra_isize 58 (inode size 256) EXT4-fs (loop4): Remounting filesystem read-only EXT4-fs error (device loop4): ext4_xattr_inode_iget:406: comm syz.4.518: error while reading EA inode 11 err=-117 EXT4-fs (loop4): Remounting filesystem read-only EXT4-fs (loop4): 1 orphan inode deleted EXT4-fs (loop4): mounted filesystem without journal. Opts: data_err=ignore,dioread_nolock,debug_want_extra_isize=0x000000000000005a,errors=remount-ro,max_dir_size_kb=0x0000000000000004,debug_want_extra_isize=0x000000000000003a,min_batch_time=0x0000000000000003,jqfmt=vfsold,. Quota mode: none. EXT4-fs error (device loop4): htree_dirblock_to_tree:1112: inode #2: block 13: comm syz.4.518: bad entry in directory: rec_len is smaller than minimal - offset=76, inode=0, rec_len=0, size=1024 fake=0 EXT4-fs (loop4): Remounting filesystem read-only