EXT4-fs (loop9): ext4_check_descriptors: Block bitmap for group 0 overlaps superblock
EXT4-fs (loop9): group descriptors corrupted!
======================================================
WARNING: possible circular locking dependency detected
6.15.0-rc6-syzkaller-00080-g1a80a098c606 #0 Not tainted
------------------------------------------------------
syz.9.1701/20544 is trying to acquire lock:
ffff888031b7dbe0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:193
but task is already holding lock:
ffff88801aef5148 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_fop_readdir+0x264/0x870 fs/kernfs/dir.c:1890
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&root->kernfs_rwsem){++++}-{4:4}:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866
down_write+0x96/0x1f0 kernel/locking/rwsem.c:1577
kernfs_add_one+0x41/0x520 fs/kernfs/dir.c:791
kernfs_create_dir_ns+0xde/0x130 fs/kernfs/dir.c:1091
sysfs_create_dir_ns+0x123/0x280 fs/sysfs/dir.c:59
create_dir lib/kobject.c:73 [inline]
kobject_add_internal+0x59f/0xb40 lib/kobject.c:240
kobject_add_varg lib/kobject.c:374 [inline]
kobject_init_and_add+0x125/0x190 lib/kobject.c:457
btrfs_sysfs_add_qgroups+0x111/0x2b0 fs/btrfs/sysfs.c:2616
btrfs_quota_enable+0x278/0x1d50 fs/btrfs/qgroup.c:1030
btrfs_ioctl_quota_ctl+0x183/0x1c0 fs/btrfs/ioctl.c:3676
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #3 (&fs_info->qgroup_ioctl_lock){+.+.}-{4:4}:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866
__mutex_lock_common kernel/locking/mutex.c:601 [inline]
__mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746
btrfs_quota_enable+0x2be/0x1d50 fs/btrfs/qgroup.c:1059
btrfs_ioctl_quota_ctl+0x183/0x1c0 fs/btrfs/ioctl.c:3676
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #2 (btrfs_trans_num_extwriters){++++}-{0:0}:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866
join_transaction+0x1a4/0xd70 fs/btrfs/transaction.c:321
start_transaction+0x6ae/0x1620 fs/btrfs/transaction.c:705
btrfs_rebuild_free_space_tree+0xb1/0x4e0 fs/btrfs/free-space-tree.c:1317
btrfs_start_pre_rw_mount+0xd76/0x1180 fs/btrfs/disk-io.c:3074
open_ctree+0x2075/0x2800 fs/btrfs/disk-io.c:3614
btrfs_fill_super+0x19d/0x2e0 fs/btrfs/super.c:972
btrfs_get_tree_super fs/btrfs/super.c:1897 [inline]
btrfs_get_tree+0x107c/0x1620 fs/btrfs/super.c:2092
vfs_get_tree+0x8f/0x2b0 fs/super.c:1759
fc_mount+0x1c/0xb0 fs/namespace.c:1289
btrfs_get_tree_subvol fs/btrfs/super.c:2050 [inline]
btrfs_get_tree+0x67d/0x1620 fs/btrfs/super.c:2093
vfs_get_tree+0x8f/0x2b0 fs/super.c:1759
do_new_mount+0x24a/0xa40 fs/namespace.c:3881
do_mount fs/namespace.c:4221 [inline]
__do_sys_mount fs/namespace.c:4432 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4409
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (btrfs_trans_num_writers){++++}-{0:0}:
reacquire_held_locks+0x127/0x1d0 kernel/locking/lockdep.c:5383
__lock_release kernel/locking/lockdep.c:5572 [inline]
lock_release+0x1b4/0x3e0 kernel/locking/lockdep.c:5887
percpu_up_read include/linux/percpu-rwsem.h:100 [inline]
__sb_end_write include/linux/fs.h:1778 [inline]
sb_end_intwrite+0x26/0x1c0 include/linux/fs.h:1895
__btrfs_end_transaction+0x248/0x640 fs/btrfs/transaction.c:1075
btrfs_dirty_inode+0x14c/0x190 fs/btrfs/inode.c:6143
inode_update_time fs/inode.c:2076 [inline]
touch_atime+0x2f9/0x6d0 fs/inode.c:2149
file_accessed include/linux/fs.h:2599 [inline]
btrfs_file_mmap+0xbf/0x120 fs/btrfs/file.c:1938
call_mmap include/linux/fs.h:2243 [inline]
mmap_file mm/internal.h:167 [inline]
__mmap_new_file_vma mm/vma.c:2353 [inline]
__mmap_new_vma mm/vma.c:2417 [inline]
__mmap_region mm/vma.c:2519 [inline]
mmap_region+0x103e/0x1e50 mm/vma.c:2597
do_mmap+0xc68/0x1100 mm/mmap.c:561
vm_mmap_pgoff+0x31b/0x4c0 mm/util.c:579
ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:607
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&mm->mmap_lock){++++}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3166 [inline]
check_prevs_add kernel/locking/lockdep.c:3285 [inline]
validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3909
__lock_acquire+0xaac/0xd20 kernel/locking/lockdep.c:5235
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866
down_read_killable+0x50/0x350 kernel/locking/rwsem.c:1547
mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:193
get_mmap_lock_carefully mm/memory.c:6355 [inline]
lock_mm_and_find_vma+0x2a8/0x300 mm/memory.c:6406
do_user_addr_fault+0x331/0x1390 arch/x86/mm/fault.c:1360
handle_page_fault arch/x86/mm/fault.c:1480 [inline]
exc_page_fault+0x68/0x110 arch/x86/mm/fault.c:1538
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
filldir+0x2a7/0x690 fs/readdir.c:-1
dir_emit include/linux/fs.h:3861 [inline]
kernfs_fop_readdir+0x537/0x870 fs/kernfs/dir.c:1907
iterate_dir+0x5af/0x770 fs/readdir.c:108
__do_sys_getdents fs/readdir.c:322 [inline]
__se_sys_getdents+0xe4/0x250 fs/readdir.c:308
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
&mm->mmap_lock --> &fs_info->qgroup_ioctl_lock --> &root->kernfs_rwsem
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
rlock(&root->kernfs_rwsem);
lock(&fs_info->qgroup_ioctl_lock);
lock(&root->kernfs_rwsem);
rlock(&mm->mmap_lock);
*** DEADLOCK ***
3 locks held by syz.9.1701/20544:
#0: ffff888030e3cb78 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213
#1: ffff888079b6b8a0 (&type->i_mutex_dir_key#6){++++}-{4:4}, at: iterate_dir+0x49f/0x770 fs/readdir.c:101
#2: ffff88801aef5148 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_fop_readdir+0x264/0x870 fs/kernfs/dir.c:1890
stack backtrace:
CPU: 1 UID: 0 PID: 20544 Comm: syz.9.1701 Not tainted 6.15.0-rc6-syzkaller-00080-g1a80a098c606 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2079
check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2211
check_prev_add kernel/locking/lockdep.c:3166 [inline]
check_prevs_add kernel/locking/lockdep.c:3285 [inline]
validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3909
__lock_acquire+0xaac/0xd20 kernel/locking/lockdep.c:5235
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866
down_read_killable+0x50/0x350 kernel/locking/rwsem.c:1547
mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:193
get_mmap_lock_carefully mm/memory.c:6355 [inline]
lock_mm_and_find_vma+0x2a8/0x300 mm/memory.c:6406
do_user_addr_fault+0x331/0x1390 arch/x86/mm/fault.c:1360
handle_page_fault arch/x86/mm/fault.c:1480 [inline]
exc_page_fault+0x68/0x110 arch/x86/mm/fault.c:1538
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:filldir+0x2a7/0x690 fs/readdir.c:291
Code: 39 f4 0f 82 58 02 00 00 4d 39 fc 0f 87 4f 02 00 00 0f 01 cb 0f ae e8 48 8b 44 24 20 49 89 46 08 48 8b 4c 24 40 48 8b 44 24 60 <48> 89 01 48 8b 44 24 10 8b 54 24 2c 66 89 41 10 89 c0 88 54 01 ff
RSP: 0018:ffffc90004bafc68 EFLAGS: 00050283
RAX: 0000000000000151 RBX: ffffc90004bafe50 RCX: 0000200000002000
RDX: 0000000000000000 RSI: 0000200000001fe0 RDI: 0000200000002020
RBP: 000000000000000a R08: ffff88802bf95a07 R09: 1ffff110057f2b40
R10: dffffc0000000000 R11: ffffed10057f2b41 R12: 0000200000002020
R13: ffff88802c2fc2a0 R14: 0000200000001fe0 R15: 00007ffffffff000
dir_emit include/linux/fs.h:3861 [inline]
kernfs_fop_readdir+0x537/0x870 fs/kernfs/dir.c:1907
iterate_dir+0x5af/0x770 fs/readdir.c:108
__do_sys_getdents fs/readdir.c:322 [inline]
__se_sys_getdents+0xe4/0x250 fs/readdir.c:308
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9c7058e969
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:00007f9c714cd038 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 00007f9c707b5fa0 RCX: 00007f9c7058e969
RDX: 00000000000000b8 RSI: 0000200000001fc0 RDI: 0000000000000003
RBP: 00007f9c70610ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9c707b5fa0 R15: 00007ffe34f898b8
</TASK>
----------------
Code disassembly (best guess):
0: 39 f4 cmp %esi,%esp
2: 0f 82 58 02 00 00 jb 0x260
8: 4d 39 fc cmp %r15,%r12
b: 0f 87 4f 02 00 00 ja 0x260
11: 0f 01 cb stac
14: 0f ae e8 lfence
17: 48 8b 44 24 20 mov 0x20(%rsp),%rax
1c: 49 89 46 08 mov %rax,0x8(%r14)
20: 48 8b 4c 24 40 mov 0x40(%rsp),%rcx
25: 48 8b 44 24 60 mov 0x60(%rsp),%rax
* 2a: 48 89 01 mov %rax,(%rcx) <-- trapping instruction
2d: 48 8b 44 24 10 mov 0x10(%rsp),%rax
32: 8b 54 24 2c mov 0x2c(%rsp),%edx
36: 66 89 41 10 mov %ax,0x10(%rcx)
3a: 89 c0 mov %eax,%eax
3c: 88 54 01 ff mov %dl,-0x1(%rcx,%rax,1)