====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.4.2582/15640 is trying to acquire lock: ffff888077ddc650 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1811 [inline] ffff888077ddc650 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1928 [inline] ffff888077ddc650 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x444/0x1080 fs/ext4/inode.c:243 but task is already holding lock: ffff888024e36bd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x2c4/0xe50 fs/ext4/migrate.c:438 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+0x46/0x1b0 include/linux/percpu-rwsem.h:51 ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 do_writepages+0x48d/0x6d0 mm/page-writeback.c:2386 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657 writeback_single_inode+0x221/0x8b0 fs/fs-writeback.c:1770 write_inode_now+0x217/0x280 fs/fs-writeback.c:2811 iput_final fs/inode.c:1756 [inline] iput+0x5ab/0x8a0 fs/inode.c:1795 ext4_xattr_set_entry+0x10ff/0x3d30 fs/ext4/xattr.c:1837 ext4_xattr_block_set+0x4f7/0x2d30 fs/ext4/xattr.c:1936 ext4_xattr_move_to_block fs/ext4/xattr.c:2633 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2708 [inline] ext4_expand_extra_isize_ea+0xf4b/0x19a0 fs/ext4/xattr.c:2800 __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:5901 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5944 [inline] __ext4_mark_inode_dirty+0x469/0x700 fs/ext4/inode.c:6022 ext4_evict_inode+0xa81/0x1080 fs/ext4/inode.c:282 evict+0x485/0x870 fs/inode.c:647 ext4_orphan_cleanup+0xaa9/0x12e0 fs/ext4/orphan.c:470 ext4_fill_super+0x92f0/0x9a60 fs/ext4/super.c:4975 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+0x2d6/0x3c0 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 -> #0 (sb_internal){.+.+}-{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+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 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+0x444/0x1080 fs/ext4/inode.c:243 evict+0x485/0x870 fs/inode.c:647 ext4_ext_migrate+0xc0a/0xe50 fs/ext4/migrate.c:588 __ext4_ioctl fs/ext4/ioctl.c:1028 [inline] ext4_ioctl+0x18a5/0x3590 fs/ext4/ioctl.c:1282 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 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); lock(sb_internal); *** DEADLOCK *** 3 locks held by syz.4.2582/15640: #0: ffff888077ddc460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:430 #1: ffff88805b5817e0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff88805b5817e0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: __ext4_ioctl fs/ext4/ioctl.c:1027 [inline] #1: ffff88805b5817e0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_ioctl+0x189d/0x3590 fs/ext4/ioctl.c:1282 #2: ffff888024e36bd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x2c4/0xe50 fs/ext4/migrate.c:438 stack backtrace: CPU: 0 PID: 15640 Comm: syz.4.2582 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 check_noncircular+0x274/0x310 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+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 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+0x444/0x1080 fs/ext4/inode.c:243 evict+0x485/0x870 fs/inode.c:647 ext4_ext_migrate+0xc0a/0xe50 fs/ext4/migrate.c:588 __ext4_ioctl fs/ext4/ioctl.c:1028 [inline] ext4_ioctl+0x18a5/0x3590 fs/ext4/ioctl.c:1282 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 RIP: 0033:0x7fe5bdc7a749 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:00007fe5bbee1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe5bded0fa0 RCX: 00007fe5bdc7a749 RDX: 0000000000000000 RSI: 0000000000006609 RDI: 0000000000000004 RBP: 00007fe5bdcfef91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe5bded1038 R14: 00007fe5bded0fa0 R15: 00007ffc39b15828