loop4: detected capacity change from 0 to 4096 EXT4-fs (loop4): mounted filesystem without journal. Opts: ,errors=continue. Quota mode: writeback. ====================================================== WARNING: possible circular locking dependency detected 5.15.0-rc2-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/9840 is trying to acquire lock: ffff8880691df0a8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x4d/0x420 fs/quota/dquot.c:474 but task is already holding lock: ffff888149314278 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x5e1/0x17d0 fs/ext4/inode.c:630 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+0x9a/0x440 kernel/locking/rwsem.c:1464 ext4_map_blocks+0x381/0x17d0 fs/ext4/inode.c:560 ext4_getblk+0x144/0x6b0 fs/ext4/inode.c:847 ext4_bread+0x2a/0x1c0 fs/ext4/inode.c:900 ext4_quota_write+0x26d/0x690 fs/ext4/super.c:6470 write_blk+0x12e/0x220 fs/quota/quota_tree.c:64 get_free_dqblk+0x104/0x2c0 fs/quota/quota_tree.c:93 do_insert_tree+0x63a/0x11f0 fs/quota/quota_tree.c:300 do_insert_tree+0xd90/0x11f0 fs/quota/quota_tree.c:331 do_insert_tree+0xd90/0x11f0 fs/quota/quota_tree.c:331 do_insert_tree+0xd90/0x11f0 fs/quota/quota_tree.c:331 dq_insert_tree fs/quota/quota_tree.c:357 [inline] qtree_write_dquot+0x3b0/0x570 fs/quota/quota_tree.c:376 v2_write_dquot+0x11c/0x250 fs/quota/quota_v2.c:358 dquot_acquire+0x2c5/0x590 fs/quota/dquot.c:441 ext4_acquire_dquot+0x254/0x3b0 fs/ext4/super.c:6139 dqget+0x679/0x1080 fs/quota/dquot.c:899 __dquot_initialize+0x560/0xbe0 fs/quota/dquot.c:1477 ext4_create+0x90/0x4d0 fs/ext4/namei.c:2739 lookup_open.isra.0+0xfe4/0x13d0 fs/namei.c:3282 open_last_lookups fs/namei.c:3352 [inline] path_openat+0x9a5/0x2740 fs/namei.c:3558 do_filp_open+0x1aa/0x400 fs/namei.c:3588 do_sys_openat2+0x16d/0x4d0 fs/open.c:1200 do_sys_open fs/open.c:1216 [inline] __do_sys_creat fs/open.c:1290 [inline] __se_sys_creat fs/open.c:1284 [inline] __x64_sys_creat+0xc9/0x120 fs/open.c:1284 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}: down_read+0x9a/0x440 kernel/locking/rwsem.c:1464 v2_read_dquot+0x49/0x120 fs/quota/quota_v2.c:332 dquot_acquire+0x12e/0x590 fs/quota/dquot.c:432 ext4_acquire_dquot+0x254/0x3b0 fs/ext4/super.c:6139 dqget+0x679/0x1080 fs/quota/dquot.c:899 __dquot_initialize+0x560/0xbe0 fs/quota/dquot.c:1477 ext4_create+0x90/0x4d0 fs/ext4/namei.c:2739 lookup_open.isra.0+0xfe4/0x13d0 fs/namei.c:3282 open_last_lookups fs/namei.c:3352 [inline] path_openat+0x9a5/0x2740 fs/namei.c:3558 do_filp_open+0x1aa/0x400 fs/namei.c:3588 do_sys_openat2+0x16d/0x4d0 fs/open.c:1200 do_sys_open fs/open.c:1216 [inline] __do_sys_creat fs/open.c:1290 [inline] __se_sys_creat fs/open.c:1284 [inline] __x64_sys_creat+0xc9/0x120 fs/open.c:1284 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #0 (&dquot->dq_lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add kernel/locking/lockdep.c:3174 [inline] validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __mutex_lock_common kernel/locking/mutex.c:596 [inline] __mutex_lock+0x131/0x12f0 kernel/locking/mutex.c:729 dquot_commit+0x4d/0x420 fs/quota/dquot.c:474 ext4_write_dquot+0x24e/0x310 fs/ext4/super.c:6123 ext4_mark_dquot_dirty fs/ext4/super.c:6171 [inline] ext4_mark_dquot_dirty+0x111/0x1b0 fs/ext4/super.c:6165 mark_dquot_dirty fs/quota/dquot.c:345 [inline] mark_all_dquot_dirty fs/quota/dquot.c:383 [inline] __dquot_alloc_space+0x5d4/0xb60 fs/quota/dquot.c:1707 dquot_alloc_space_nodirty include/linux/quotaops.h:297 [inline] dquot_alloc_space include/linux/quotaops.h:310 [inline] dquot_alloc_block include/linux/quotaops.h:334 [inline] ext4_mb_new_blocks+0x5b3/0x5230 fs/ext4/mballoc.c:5548 ext4_ext_map_blocks+0x1fa4/0x6140 fs/ext4/extents.c:4250 ext4_map_blocks+0x653/0x17d0 fs/ext4/inode.c:637 _ext4_get_block+0x241/0x590 fs/ext4/inode.c:793 ext4_block_write_begin+0x503/0x1110 fs/ext4/inode.c:1078 ext4_write_begin+0x4be/0x14c0 fs/ext4/inode.c:1202 ext4_da_write_begin+0x686/0x11c0 fs/ext4/inode.c:2966 generic_perform_write+0x202/0x510 mm/filemap.c:3770 ext4_buffered_write_iter+0x244/0x500 fs/ext4/file.c:269 ext4_file_write_iter+0x423/0x14e0 fs/ext4/file.c:680 call_write_iter include/linux/fs.h:2163 [inline] new_sync_write+0x429/0x660 fs/read_write.c:507 vfs_write+0x7cf/0xae0 fs/read_write.c:594 ksys_write+0x12d/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae 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-executor.4/9840: #0: ffff88801f5038f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 #1: ffff88803f854460 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x12d/0x250 fs/read_write.c:647 #2: ffff8881493143f0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:786 [inline] #2: ffff8881493143f0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_buffered_write_iter+0xb6/0x500 fs/ext4/file.c:263 #3: ffff888149314278 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x5e1/0x17d0 fs/ext4/inode.c:630 #4: ffffffff8bb380f8 (dquot_srcu){....}-{0:0}, at: i_dquot fs/quota/dquot.c:924 [inline] #4: ffffffff8bb380f8 (dquot_srcu){....}-{0:0}, at: __dquot_alloc_space+0x1b4/0xb60 fs/quota/dquot.c:1669 stack backtrace: CPU: 1 PID: 9840 Comm: syz-executor.4 Not tainted 5.15.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2131 check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add kernel/locking/lockdep.c:3174 [inline] validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __mutex_lock_common kernel/locking/mutex.c:596 [inline] __mutex_lock+0x131/0x12f0 kernel/locking/mutex.c:729 dquot_commit+0x4d/0x420 fs/quota/dquot.c:474 ext4_write_dquot+0x24e/0x310 fs/ext4/super.c:6123 ext4_mark_dquot_dirty fs/ext4/super.c:6171 [inline] ext4_mark_dquot_dirty+0x111/0x1b0 fs/ext4/super.c:6165 mark_dquot_dirty fs/quota/dquot.c:345 [inline] mark_all_dquot_dirty fs/quota/dquot.c:383 [inline] __dquot_alloc_space+0x5d4/0xb60 fs/quota/dquot.c:1707 dquot_alloc_space_nodirty include/linux/quotaops.h:297 [inline] dquot_alloc_space include/linux/quotaops.h:310 [inline] dquot_alloc_block include/linux/quotaops.h:334 [inline] ext4_mb_new_blocks+0x5b3/0x5230 fs/ext4/mballoc.c:5548 ext4_ext_map_blocks+0x1fa4/0x6140 fs/ext4/extents.c:4250 ext4_map_blocks+0x653/0x17d0 fs/ext4/inode.c:637 _ext4_get_block+0x241/0x590 fs/ext4/inode.c:793 ext4_block_write_begin+0x503/0x1110 fs/ext4/inode.c:1078 ext4_write_begin+0x4be/0x14c0 fs/ext4/inode.c:1202 ext4_da_write_begin+0x686/0x11c0 fs/ext4/inode.c:2966 generic_perform_write+0x202/0x510 mm/filemap.c:3770 ext4_buffered_write_iter+0x244/0x500 fs/ext4/file.c:269 ext4_file_write_iter+0x423/0x14e0 fs/ext4/file.c:680 call_write_iter include/linux/fs.h:2163 [inline] new_sync_write+0x429/0x660 fs/read_write.c:507 vfs_write+0x7cf/0xae0 fs/read_write.c:594 ksys_write+0x12d/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc2bf0a0709 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc2bc617188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fc2bf1a4f60 RCX: 00007fc2bf0a0709 RDX: 000000000d4ba0ff RSI: 00000000200009c0 RDI: 0000000000000005 RBP: 00007fc2bf0facb4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd3527cd1f R14: 00007fc2bc617300 R15: 0000000000022000