ref_ctr going negative. vaddr: 0x200000fe9002, curr val: -3596, delta: 1
ref_ctr increment failed for inode: 0x12 offset: 0x0 ref_ctr_offset: 0x2 of mm: 0xffff888011a3eb80
loop0: detected capacity change from 0 to 32768
bcachefs (loop0): starting version 1.7: mi_btree_bitmap opts=metadata_checksum=none,data_checksum=none,compression=lz4,grpquota,nojournal_transaction_names
  allowing incompatible features above 0.0: (unknown version)
  features: lz4,new_siphash,inline_data,new_extent_overwrite,btree_ptr_v2,new_varint,journal_no_flush,alloc_v2,extents_across_btree_nodes
bcachefs (loop0): Using encoding defined by superblock: utf8-12.1.0
bcachefs (loop0): invalid journal entry, version=1.7: mi_btree_bitmap type=data_usage in superblock: invalid journal entry usage: bad size, shutting down
  error not marked as autofix and not in fsck
  run fsck, and forward to devs so error can be marked for self-healing
  emergency read only at seq 0
bcachefs (loop0): error in recovery: fsck_errors_not_fixed
bcachefs (loop0): bch2_fs_start(): error starting filesystem fsck_errors_not_fixed
bcachefs (loop0): shutting down
bcachefs (loop0): shutdown complete
bcachefs: bch2_fs_get_tree() error: fsck_errors_not_fixed
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 0 P4D 0 
Oops: Oops: 0010 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5364 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc9000d337998 EFLAGS: 00010287
RAX: ffffffff81f8ec84 RBX: 1ffffd400029d558 RCX: 0000000000100000
RDX: ffffc9000e292000 RSI: ffffea00014eaac0 RDI: ffff8880336451c0
RBP: ffffc9000d337a50 R08: ffffea00014eaac7 R09: 1ffffd400029d558
R10: dffffc0000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffea00014eaac8 R14: ffffea00014eaac0 R15: 1ffffd400029d559
FS:  00007f200c44b6c0(0000) GS:ffff88808d007000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000042e92000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 filemap_read_folio+0x117/0x380 mm/filemap.c:2413
 do_read_cache_folio+0x350/0x590 mm/filemap.c:3957
 freader_get_folio+0x3c4/0x830 lib/buildid.c:77
 freader_fetch+0xa3/0x5d0 lib/buildid.c:120
 __build_id_parse+0x133/0x7d0 lib/buildid.c:305
 do_procmap_query fs/proc/task_mmu.c:662 [inline]
 procfs_procmap_ioctl+0x7f0/0xce0 fs/proc/task_mmu.c:741
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:598 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:584
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f200b58eec9
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:00007f200c44b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f200b7e5fa0 RCX: 00007f200b58eec9
RDX: 0000200000000180 RSI: 00000000c0686611 RDI: 000000000000000a
RBP: 00007f200b611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f200b7e6038 R14: 00007f200b7e5fa0 R15: 00007fffe1e35d88
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 0000000000000000 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc9000d337998 EFLAGS: 00010287
RAX: ffffffff81f8ec84 RBX: 1ffffd400029d558 RCX: 0000000000100000
RDX: ffffc9000e292000 RSI: ffffea00014eaac0 RDI: ffff8880336451c0
RBP: ffffc9000d337a50 R08: ffffea00014eaac7 R09: 1ffffd400029d558
R10: dffffc0000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffea00014eaac8 R14: ffffea00014eaac0 R15: 1ffffd400029d559
FS:  00007f200c44b6c0(0000) GS:ffff88808d007000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000042e92000 CR4: 0000000000352ef0