ext4 filesystem being mounted at /365/file0aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa supports timestamps until 2038-01-19 (0x7fffffff) ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.6.2751/16898 is trying to acquire lock: ffff88805bbc4608 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline] ffff88805bbc4608 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1755 [inline] ffff88805bbc4608 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x2b9/0xea0 fs/ext4/inode.c:213 but task is already holding lock: ffff88807b1b8bd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_write fs/ext4/ext4.h:1779 [inline] ffff88807b1b8bd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x2f1/0xff0 fs/ext4/migrate.c:437 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 (sb_internal){.+.+}-{0:0}: 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 percpu_down_read+0x44/0x1a0 include/linux/percpu-rwsem.h:51 __sb_start_write include/linux/fs.h:1633 [inline] sb_start_intwrite include/linux/fs.h:1755 [inline] ext4_evict_inode+0x2b9/0xea0 fs/ext4/inode.c:213 evict+0x486/0x870 fs/inode.c:705 ext4_ext_migrate+0xcfb/0xff0 fs/ext4/migrate.c:587 __ext4_ioctl fs/ext4/ioctl.c:1409 [inline] ext4_ioctl+0x1c4b/0x3820 fs/ext4/ioctl.c:1627 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 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 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sbi->s_writepages_rwsem); lock(sb_internal); lock(&sbi->s_writepages_rwsem); rlock(sb_internal); *** DEADLOCK *** 3 locks held by syz.6.2751/16898: #0: ffff88805bbc4418 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x200 fs/namespace.c:456 #1: ffff88805de1de10 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #1: ffff88805de1de10 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: __ext4_ioctl fs/ext4/ioctl.c:1408 [inline] #1: ffff88805de1de10 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_ioctl+0x1c43/0x3820 fs/ext4/ioctl.c:1627 #2: ffff88807b1b8bd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_write fs/ext4/ext4.h:1779 [inline] #2: ffff88807b1b8bd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x2f1/0xff0 fs/ext4/migrate.c:437 stack backtrace: CPU: 0 PID: 16898 Comm: syz.6.2751 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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 percpu_down_read+0x44/0x1a0 include/linux/percpu-rwsem.h:51 __sb_start_write include/linux/fs.h:1633 [inline] sb_start_intwrite include/linux/fs.h:1755 [inline] ext4_evict_inode+0x2b9/0xea0 fs/ext4/inode.c:213 evict+0x486/0x870 fs/inode.c:705 ext4_ext_migrate+0xcfb/0xff0 fs/ext4/migrate.c:587 __ext4_ioctl fs/ext4/ioctl.c:1409 [inline] ext4_ioctl+0x1c4b/0x3820 fs/ext4/ioctl.c:1627 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 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 RIP: 0033:0x7fb44198f6c9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb44285d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fb441be5fa0 RCX: 00007fb44198f6c9 RDX: 0000000000000000 RSI: 0000000000006609 RDI: 0000000000000004 RBP: 00007fb441a11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb441be6038 R14: 00007fb441be5fa0 R15: 00007fff48ee15b8 EXT4-fs (loop6): unmounting filesystem 76b65be2-f6da-4727-8c75-0525a5b65a09.