====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.6.728/7745 is trying to acquire lock: ffff8880543d8b28 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x5a/0x410 fs/quota/dquot.c:507 but task is already holding lock: ffff8880717c1698 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x987/0x1230 fs/ext4/inode.c:4284 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&ei->i_data_sem/2){++++}-{3:3}: 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_write+0x230/0x570 fs/ext4/super.c:7203 write_blk fs/quota/quota_tree.c:70 [inline] get_free_dqblk+0x312/0x660 fs/quota/quota_tree.c:136 do_insert_tree+0x22b/0x1040 fs/quota/quota_tree.c:347 do_insert_tree+0x9eb/0x1040 fs/quota/quota_tree.c:402 do_insert_tree+0x9eb/0x1040 fs/quota/quota_tree.c:402 do_insert_tree+0x9eb/0x1040 fs/quota/quota_tree.c:402 dq_insert_tree fs/quota/quota_tree.c:432 [inline] qtree_write_dquot+0x48d/0x5b0 fs/quota/quota_tree.c:451 v2_write_dquot+0x108/0x190 fs/quota/quota_v2.c:361 dquot_acquire+0x2d5/0x520 fs/quota/dquot.c:472 ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6812 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:5537 [inline] ext4_fill_super+0x7bc2/0x8150 fs/ext4/super.c:5668 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:3069 do_mount fs/namespace.c:3412 [inline] __do_sys_mount fs/namespace.c:3620 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3597 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 (&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:6812 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:5537 [inline] ext4_fill_super+0x7bc2/0x8150 fs/ext4/super.c:5668 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:3069 do_mount fs/namespace.c:3412 [inline] __do_sys_mount fs/namespace.c:3620 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3597 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 (&dquot->dq_lock){+.+.}-{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 __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:6792 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:6138 [inline] ext4_free_blocks+0x1bab/0x2640 fs/ext4/mballoc.c:6268 ext4_clear_blocks+0x36c/0x3e0 fs/ext4/indirect.c:895 ext4_free_data fs/ext4/indirect.c:969 [inline] ext4_ind_truncate+0x6fb/0xb20 fs/ext4/indirect.c:1161 ext4_truncate+0x9e0/0x1230 fs/ext4/inode.c:4291 ext4_setattr+0x10cb/0x19f0 fs/ext4/inode.c:5631 notify_change+0xc74/0xf40 fs/attr.c:499 do_truncate+0x197/0x220 fs/open.c:65 handle_truncate fs/namei.c:3285 [inline] do_open fs/namei.c:3630 [inline] path_openat+0x27f2/0x2e70 fs/namei.c:3783 do_filp_open+0x1c1/0x3c0 fs/namei.c:3810 do_sys_openat2+0x142/0x490 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_openat fs/open.c:1350 [inline] __se_sys_openat fs/open.c:1345 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1345 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: &dquot->dq_lock --> &s->s_dquot.dqio_sem --> &ei->i_data_sem/2 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ei->i_data_sem/2); lock(&s->s_dquot.dqio_sem); lock(&ei->i_data_sem/2); lock(&dquot->dq_lock); *** DEADLOCK *** 5 locks held by syz.6.728/7745: #0: ffff88802f696460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:393 #1: ffff8880717c1810 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff8880717c1810 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: do_truncate+0x183/0x220 fs/open.c:63 #2: ffff8880717c19b0 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_invalidate_lock include/linux/fs.h:803 [inline] #2: ffff8880717c19b0 (mapping.invalidate_lock){++++}-{3:3}, at: ext4_setattr+0xe6f/0x19f0 fs/ext4/inode.c:5554 #3: ffff8880717c1698 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x987/0x1230 fs/ext4/inode.c:4284 #4: ffffffff8cc72e88 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #4: ffffffff8cc72e88 (dquot_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #4: ffffffff8cc72e88 (dquot_srcu){....}-{0:0}, at: __dquot_free_space+0x174/0xbc0 fs/quota/dquot.c:1915 stack backtrace: CPU: 1 PID: 7745 Comm: syz.6.728 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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 __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:6792 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:6138 [inline] ext4_free_blocks+0x1bab/0x2640 fs/ext4/mballoc.c:6268 ext4_clear_blocks+0x36c/0x3e0 fs/ext4/indirect.c:895 ext4_free_data fs/ext4/indirect.c:969 [inline] ext4_ind_truncate+0x6fb/0xb20 fs/ext4/indirect.c:1161 ext4_truncate+0x9e0/0x1230 fs/ext4/inode.c:4291 ext4_setattr+0x10cb/0x19f0 fs/ext4/inode.c:5631 notify_change+0xc74/0xf40 fs/attr.c:499 do_truncate+0x197/0x220 fs/open.c:65 handle_truncate fs/namei.c:3285 [inline] do_open fs/namei.c:3630 [inline] path_openat+0x27f2/0x2e70 fs/namei.c:3783 do_filp_open+0x1c1/0x3c0 fs/namei.c:3810 do_sys_openat2+0x142/0x490 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_openat fs/open.c:1350 [inline] __se_sys_openat fs/open.c:1345 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1345 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: 0033:0x7fe57398eba9 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:00007fe57482c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fe573bd6180 RCX: 00007fe57398eba9 RDX: 0000000000103a42 RSI: 0000200000000440 RDI: ffffffffffffff9c RBP: 00007fe573a11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000032 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe573bd6218 R14: 00007fe573bd6180 R15: 00007fff590f0dd8