====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.5.1139/7924 is trying to acquire lock: ffff88804f0366d8 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x323/0x1b70 fs/ext4/inode.c:604 but task is already holding lock: ffff888059992208 (&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:6831 dqget+0x778/0xeb0 fs/quota/dquot.c:988 __dquot_initialize+0x3c3/0xcd0 fs/quota/dquot.c:1517 ext4_xattr_set+0xd8/0x320 fs/ext4/xattr.c:2485 __vfs_setxattr+0x3e0/0x420 fs/xattr.c:182 __vfs_setxattr_noperm+0x129/0x5e0 fs/xattr.c:216 vfs_setxattr+0x167/0x2e0 fs/xattr.c:309 do_setxattr fs/xattr.c:594 [inline] setxattr+0x346/0x360 fs/xattr.c:617 path_setxattr+0x147/0x290 fs/xattr.c:636 __do_sys_lsetxattr fs/xattr.c:659 [inline] __se_sys_lsetxattr fs/xattr.c:655 [inline] __x64_sys_lsetxattr+0xb4/0xd0 fs/xattr.c:655 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #1 (&dquot->dq_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747 dquot_commit+0x5a/0x410 fs/quota/dquot.c:507 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6811 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:6153 [inline] ext4_free_blocks+0x1bf3/0x26a0 fs/ext4/mballoc.c:6283 ext4_remove_blocks fs/ext4/extents.c:2537 [inline] ext4_ext_rm_leaf fs/ext4/extents.c:2703 [inline] ext4_ext_remove_space+0x202d/0x4500 fs/ext4/extents.c:2951 ext4_ext_truncate+0x179/0x2d0 fs/ext4/extents.c:4527 ext4_truncate+0xa23/0x1240 fs/ext4/inode.c:4291 ext4_setattr+0x10cb/0x19f0 fs/ext4/inode.c:5645 notify_change+0xc74/0xf40 fs/attr.c:499 do_truncate+0x1ac/0x240 fs/open.c:65 handle_truncate fs/namei.c:3293 [inline] do_open fs/namei.c:3638 [inline] path_openat+0x2861/0x2ee0 fs/namei.c:3791 do_filp_open+0x1f1/0x430 fs/namei.c:3818 do_sys_openat2+0x150/0x4b0 fs/open.c:1320 do_sys_open fs/open.c:1336 [inline] __do_sys_creat fs/open.c:1414 [inline] __se_sys_creat fs/open.c:1408 [inline] __x64_sys_creat+0x8c/0xb0 fs/open.c:1408 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 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+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520 ext4_map_blocks+0x323/0x1b70 fs/ext4/inode.c:604 ext4_getblk+0x1cc/0x6f0 fs/ext4/inode.c:890 ext4_bread+0x26/0x170 fs/ext4/inode.c:946 ext4_quota_read+0x180/0x380 fs/ext4/super.c:7176 read_blk fs/quota/quota_tree.c:61 [inline] find_tree_dqentry+0x1cd/0xf30 fs/quota/quota_tree.c:671 find_dqentry fs/quota/quota_tree.c:716 [inline] qtree_read_dquot+0x57b/0x820 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:6831 dqget+0x778/0xeb0 fs/quota/dquot.c:988 __dquot_initialize+0x3c3/0xcd0 fs/quota/dquot.c:1517 ext4_setattr+0x2ba/0x19f0 fs/ext4/inode.c:5493 notify_change+0xc74/0xf40 fs/attr.c:499 do_truncate+0x1ac/0x240 fs/open.c:65 vfs_truncate+0x262/0x2f0 fs/open.c:111 do_sys_truncate+0xf2/0x1c0 fs/open.c:134 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 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 *** 4 locks held by syz.5.1139/7924: #0: ffff888059992460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402 #1: ffff88804f1ca218 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff88804f1ca218 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: do_truncate+0x198/0x240 fs/open.c:63 #2: ffff8880562e6ce8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_acquire+0x63/0x520 fs/quota/dquot.c:460 #3: ffff888059992208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_read_dquot+0x4a/0x110 fs/quota/quota_v2.c:335 stack backtrace: CPU: 0 PID: 7924 Comm: syz.5.1139 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 check_noncircular+0x296/0x330 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+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520 ext4_map_blocks+0x323/0x1b70 fs/ext4/inode.c:604 ext4_getblk+0x1cc/0x6f0 fs/ext4/inode.c:890 ext4_bread+0x26/0x170 fs/ext4/inode.c:946 ext4_quota_read+0x180/0x380 fs/ext4/super.c:7176 read_blk fs/quota/quota_tree.c:61 [inline] find_tree_dqentry+0x1cd/0xf30 fs/quota/quota_tree.c:671 find_dqentry fs/quota/quota_tree.c:716 [inline] qtree_read_dquot+0x57b/0x820 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:6831 dqget+0x778/0xeb0 fs/quota/dquot.c:988 __dquot_initialize+0x3c3/0xcd0 fs/quota/dquot.c:1517 ext4_setattr+0x2ba/0x19f0 fs/ext4/inode.c:5493 notify_change+0xc74/0xf40 fs/attr.c:499 do_truncate+0x1ac/0x240 fs/open.c:65 vfs_truncate+0x262/0x2f0 fs/open.c:111 do_sys_truncate+0xf2/0x1c0 fs/open.c:134 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f55aeb9c819 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f55afa14028 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007f55aee15fa0 RCX: 00007f55aeb9c819 RDX: 0000000000000000 RSI: 00000020fffbfffc RDI: 0000200000000340 RBP: 00007f55aec32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f55aee16038 R14: 00007f55aee15fa0 R15: 00007ffdc040c7c8