ext4 filesystem being mounted at /422/bus supports timestamps until 2038-01-19 (0x7fffffff) ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.1.2166/13094 is trying to acquire lock: ffff88805fa325e8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x5a/0x410 fs/quota/dquot.c:507 but task is already holding lock: ffff88805f9bd238 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x97f/0x10f0 fs/ext4/inode.c:4258 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+0x44/0x2e0 kernel/locking/rwsem.c:1498 ext4_map_blocks+0x33c/0x1b30 fs/ext4/inode.c:600 ext4_getblk+0x176/0x670 fs/ext4/inode.c:872 ext4_bread+0x26/0x180 fs/ext4/inode.c:925 ext4_quota_write+0x236/0x580 fs/ext4/super.c:6623 write_blk fs/quota/quota_tree.c:64 [inline] get_free_dqblk+0x387/0x7d0 fs/quota/quota_tree.c:125 do_insert_tree+0x214/0x1970 fs/quota/quota_tree.c:335 do_insert_tree+0x5b1/0x1970 fs/quota/quota_tree.c:366 dq_insert_tree fs/quota/quota_tree.c:392 [inline] qtree_write_dquot+0x361/0x4b0 fs/quota/quota_tree.c:411 v2_write_dquot+0x108/0x190 fs/quota/quota_v2.c:358 dquot_acquire+0x2d5/0x520 fs/quota/dquot.c:472 ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6232 dqget+0x778/0xeb0 fs/quota/dquot.c:988 dquot_transfer+0x1e9/0x460 fs/quota/dquot.c:2146 ext4_setattr+0x735/0x1b60 fs/ext4/inode.c:5477 notify_change+0xbcd/0xee0 fs/attr.c:505 chown_common+0x4a7/0x660 fs/open.c:680 vfs_fchown fs/open.c:748 [inline] ksys_fchown+0xe2/0x150 fs/open.c:759 __do_sys_fchown fs/open.c:767 [inline] __se_sys_fchown fs/open.c:765 [inline] __x64_sys_fchown+0x76/0x80 fs/open.c:765 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 -> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}: down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498 v2_read_dquot+0x4a/0x110 fs/quota/quota_v2.c:332 dquot_acquire+0x152/0x520 fs/quota/dquot.c:463 ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6232 dqget+0x778/0xeb0 fs/quota/dquot.c:988 __dquot_initialize+0x3c3/0xcd0 fs/quota/dquot.c:1517 ext4_file_open+0x2e4/0x700 fs/ext4/file.c:855 do_dentry_open+0x7ff/0xf80 fs/open.c:826 do_open fs/namei.c:3616 [inline] path_openat+0x26f5/0x2fa0 fs/namei.c:3750 do_filp_open+0x1e2/0x410 fs/namei.c:3777 do_sys_openat2+0x150/0x4b0 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 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 (&dquot->dq_lock){+.+.}-{3:3}: 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+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 dquot_commit+0x5a/0x410 fs/quota/dquot.c:507 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6212 mark_dquot_dirty fs/quota/dquot.c:372 [inline] mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:412 __dquot_free_space+0x7ca/0xb90 fs/quota/dquot.c:1942 dquot_free_space_nodirty include/linux/quotaops.h:376 [inline] dquot_free_space include/linux/quotaops.h:381 [inline] dquot_free_block include/linux/quotaops.h:392 [inline] ext4_mb_clear_bb fs/ext4/mballoc.c:6164 [inline] ext4_free_blocks+0x1b2b/0x24d0 fs/ext4/mballoc.c:6294 ext4_remove_blocks fs/ext4/extents.c:2525 [inline] ext4_ext_rm_leaf fs/ext4/extents.c:2691 [inline] ext4_ext_remove_space+0x1f86/0x42b0 fs/ext4/extents.c:2939 ext4_ext_truncate+0x192/0x240 fs/ext4/extents.c:4489 ext4_truncate+0xa09/0x10f0 fs/ext4/inode.c:4263 ext4_setattr+0x1147/0x1b60 fs/ext4/inode.c:5620 notify_change+0xbcd/0xee0 fs/attr.c:505 do_truncate+0x1ac/0x240 fs/open.c:65 handle_truncate fs/namei.c:3273 [inline] do_open fs/namei.c:3620 [inline] path_openat+0x2922/0x2fa0 fs/namei.c:3750 do_filp_open+0x1e2/0x410 fs/namei.c:3777 do_sys_openat2+0x150/0x4b0 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 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: 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.1.2166/13094: #0: ffff8880783de460 (sb_writers#5){++++}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386 #1: ffff88805f9bd3b0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff88805f9bd3b0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: do_truncate+0x198/0x240 fs/open.c:63 #2: ffff88805f9bd550 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_invalidate_lock include/linux/fs.h:832 [inline] #2: ffff88805f9bd550 (mapping.invalidate_lock){++++}-{3:3}, at: ext4_setattr+0xf16/0x1b60 fs/ext4/inode.c:5543 #3: ffff88805f9bd238 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x97f/0x10f0 fs/ext4/inode.c:4258 #4: ffffffff8c4415f8 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:312 stack backtrace: CPU: 1 PID: 13094 Comm: syz.1.2166 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 check_noncircular+0x296/0x330 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+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 dquot_commit+0x5a/0x410 fs/quota/dquot.c:507 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6212 mark_dquot_dirty fs/quota/dquot.c:372 [inline] mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:412 __dquot_free_space+0x7ca/0xb90 fs/quota/dquot.c:1942 dquot_free_space_nodirty include/linux/quotaops.h:376 [inline] dquot_free_space include/linux/quotaops.h:381 [inline] dquot_free_block include/linux/quotaops.h:392 [inline] ext4_mb_clear_bb fs/ext4/mballoc.c:6164 [inline] ext4_free_blocks+0x1b2b/0x24d0 fs/ext4/mballoc.c:6294 ext4_remove_blocks fs/ext4/extents.c:2525 [inline] ext4_ext_rm_leaf fs/ext4/extents.c:2691 [inline] ext4_ext_remove_space+0x1f86/0x42b0 fs/ext4/extents.c:2939 ext4_ext_truncate+0x192/0x240 fs/ext4/extents.c:4489 ext4_truncate+0xa09/0x10f0 fs/ext4/inode.c:4263 ext4_setattr+0x1147/0x1b60 fs/ext4/inode.c:5620 notify_change+0xbcd/0xee0 fs/attr.c:505 do_truncate+0x1ac/0x240 fs/open.c:65 handle_truncate fs/namei.c:3273 [inline] do_open fs/namei.c:3620 [inline] path_openat+0x2922/0x2fa0 fs/namei.c:3750 do_filp_open+0x1e2/0x410 fs/namei.c:3777 do_sys_openat2+0x150/0x4b0 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 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: 0033:0x7f002b39fdd9 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:00007f00295d3028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f002b619090 RCX: 00007f002b39fdd9 RDX: 0000000000000242 RSI: 0000200000000180 RDI: ffffffffffffff9c RBP: 00007f002b435d69 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000018e R11: 0000000000000246 R12: 0000000000000000 R13: 00007f002b619128 R14: 00007f002b619090 R15: 00007ffe34cb6dd8