loop6: detected capacity change from 0 to 512 ====================================================== WARNING: possible circular locking dependency detected 6.1.141-syzkaller #0 Not tainted ------------------------------------------------------ syz.6.474/6338 is trying to acquire lock: ffff8880502066d8 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x316/0x1b60 fs/ext4/inode.c:604 but task is already holding lock: ffff888056a0c208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_read_dquot+0x4a/0x110 fs/quota/quota_v2.c:335 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&s->s_dquot.dqio_sem){++++}-{3:3}: down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520 v2_read_dquot+0x4a/0x110 fs/quota/quota_v2.c:335 dquot_acquire+0x152/0x520 fs/quota/dquot.c:463 ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6810 dqget+0x778/0xeb0 fs/quota/dquot.c:988 __dquot_initialize+0x3b6/0xcb0 fs/quota/dquot.c:1517 ext4_process_orphan+0x54/0x300 fs/ext4/orphan.c:329 ext4_orphan_cleanup+0xbd3/0x1400 fs/ext4/orphan.c:474 __ext4_fill_super fs/ext4/super.c:5535 [inline] ext4_fill_super+0x7b78/0x8110 fs/ext4/super.c:5666 get_tree_bdev+0x3f1/0x610 fs/super.c:1366 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x24a/0xa40 fs/namespace.c:3054 do_mount fs/namespace.c:3397 [inline] __do_sys_mount fs/namespace.c:3605 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3582 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #1 (&dquot->dq_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747 dquot_commit+0x5a/0x410 fs/quota/dquot.c:507 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6790 mark_dquot_dirty fs/quota/dquot.c:372 [inline] mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:412 __dquot_free_space+0x7ec/0xbc0 fs/quota/dquot.c:1942 dquot_free_space_nodirty include/linux/quotaops.h:379 [inline] dquot_free_space include/linux/quotaops.h:384 [inline] dquot_free_block include/linux/quotaops.h:395 [inline] ext4_mb_clear_bb fs/ext4/mballoc.c:6143 [inline] ext4_free_blocks+0x1bab/0x2640 fs/ext4/mballoc.c:6273 ext4_remove_blocks fs/ext4/extents.c:2525 [inline] ext4_ext_rm_leaf fs/ext4/extents.c:2691 [inline] ext4_ext_remove_space+0x1f0d/0x4490 fs/ext4/extents.c:2939 ext4_ext_truncate+0x211/0x370 fs/ext4/extents.c:4469 ext4_truncate+0xa0b/0x1230 fs/ext4/inode.c:4289 ext4_process_orphan+0x1cb/0x300 fs/ext4/orphan.c:339 ext4_orphan_cleanup+0xbd3/0x1400 fs/ext4/orphan.c:474 __ext4_fill_super fs/ext4/super.c:5535 [inline] ext4_fill_super+0x7b78/0x8110 fs/ext4/super.c:5666 get_tree_bdev+0x3f1/0x610 fs/super.c:1366 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x24a/0xa40 fs/namespace.c:3054 do_mount fs/namespace.c:3397 [inline] __do_sys_mount fs/namespace.c:3605 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3582 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&ei->i_data_sem/2){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520 ext4_map_blocks+0x316/0x1b60 fs/ext4/inode.c:604 ext4_getblk+0x1ab/0x6d0 fs/ext4/inode.c:890 ext4_bread+0x26/0x170 fs/ext4/inode.c:946 ext4_quota_read+0x180/0x380 fs/ext4/super.c:7155 read_blk fs/quota/quota_tree.c:61 [inline] find_tree_dqentry+0x1cd/0xf30 fs/quota/quota_tree.c:671 find_tree_dqentry+0x6b0/0xf30 fs/quota/quota_tree.c:698 find_tree_dqentry+0x6b0/0xf30 fs/quota/quota_tree.c:698 find_tree_dqentry+0x6b0/0xf30 fs/quota/quota_tree.c:698 find_dqentry fs/quota/quota_tree.c:716 [inline] qtree_read_dquot+0x558/0x7f0 fs/quota/quota_tree.c:736 v2_read_dquot+0xc0/0x110 fs/quota/quota_v2.c:336 dquot_acquire+0x152/0x520 fs/quota/dquot.c:463 ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6810 dqget+0x778/0xeb0 fs/quota/dquot.c:988 __dquot_initialize+0x328/0xcb0 fs/quota/dquot.c:1517 ext4_process_orphan+0x54/0x300 fs/ext4/orphan.c:329 ext4_orphan_cleanup+0xbd3/0x1400 fs/ext4/orphan.c:474 __ext4_fill_super fs/ext4/super.c:5535 [inline] ext4_fill_super+0x7b78/0x8110 fs/ext4/super.c:5666 get_tree_bdev+0x3f1/0x610 fs/super.c:1366 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x24a/0xa40 fs/namespace.c:3054 do_mount fs/namespace.c:3397 [inline] __do_sys_mount fs/namespace.c:3605 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3582 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Chain exists of: &ei->i_data_sem/2 --> &dquot->dq_lock --> &s->s_dquot.dqio_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&s->s_dquot.dqio_sem); lock(&dquot->dq_lock); lock(&s->s_dquot.dqio_sem); lock(&ei->i_data_sem/2); *** DEADLOCK *** 3 locks held by syz.6.474/6338: #0: ffff888056a0c0e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x930 fs/super.c:228 #1: ffff8880500acea8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_acquire+0x63/0x520 fs/quota/dquot.c:460 #2: ffff888056a0c208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_read_dquot+0x4a/0x110 fs/quota/quota_v2.c:335 stack backtrace: CPU: 1 PID: 6338 Comm: syz.6.474 Not tainted 6.1.141-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520 ext4_map_blocks+0x316/0x1b60 fs/ext4/inode.c:604 ext4_getblk+0x1ab/0x6d0 fs/ext4/inode.c:890 ext4_bread+0x26/0x170 fs/ext4/inode.c:946 ext4_quota_read+0x180/0x380 fs/ext4/super.c:7155 read_blk fs/quota/quota_tree.c:61 [inline] find_tree_dqentry+0x1cd/0xf30 fs/quota/quota_tree.c:671 find_tree_dqentry+0x6b0/0xf30 fs/quota/quota_tree.c:698 find_tree_dqentry+0x6b0/0xf30 fs/quota/quota_tree.c:698 find_tree_dqentry+0x6b0/0xf30 fs/quota/quota_tree.c:698 find_dqentry fs/quota/quota_tree.c:716 [inline] qtree_read_dquot+0x558/0x7f0 fs/quota/quota_tree.c:736 v2_read_dquot+0xc0/0x110 fs/quota/quota_v2.c:336 dquot_acquire+0x152/0x520 fs/quota/dquot.c:463 ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6810 dqget+0x778/0xeb0 fs/quota/dquot.c:988 __dquot_initialize+0x328/0xcb0 fs/quota/dquot.c:1517 ext4_process_orphan+0x54/0x300 fs/ext4/orphan.c:329 ext4_orphan_cleanup+0xbd3/0x1400 fs/ext4/orphan.c:474 __ext4_fill_super fs/ext4/super.c:5535 [inline] ext4_fill_super+0x7b78/0x8110 fs/ext4/super.c:5666 get_tree_bdev+0x3f1/0x610 fs/super.c:1366 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x24a/0xa40 fs/namespace.c:3054 do_mount fs/namespace.c:3397 [inline] __do_sys_mount fs/namespace.c:3605 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3582 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7faf02b900ca Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007faf03a4de68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007faf03a4def0 RCX: 00007faf02b900ca RDX: 0000200000000040 RSI: 0000200000000000 RDI: 00007faf03a4deb0 RBP: 0000200000000040 R08: 00007faf03a4def0 R09: 0000000002000008 R10: 0000000002000008 R11: 0000000000000246 R12: 0000200000000000 R13: 00007faf03a4deb0 R14: 000000000000052e R15: 00002000000001c0 Quota error (device loop6): do_check_range: Getting dqdh_prev_free 1536 out of range 0-5 Quota error (device loop6): qtree_write_dquot: Error -117 occurred while creating quota EXT4-fs error (device loop6): ext4_acquire_dquot:6814: comm syz.6.474: Failed to acquire dquot type 1 EXT4-fs (loop6): 1 truncate cleaned up EXT4-fs (loop6): mounted filesystem without journal. Quota mode: writeback. ext4 filesystem being mounted at /44/file0 supports timestamps until 2038-01-19 (0x7fffffff) EXT4-fs (loop6): unmounting filesystem.