bcachefs (loop0): btree node read error at btree freespace level 0/0
  u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq e81e1ed936acf3df written 32 min_key POS_MIN durability: 1 ptr: 0:29:0 gen 0
  loop0 node offset 0/32 bset u64s 0: first btree node bset has blacklisted journal seq (0)
  loop0 node offset 0/32 bset u64s 0: found blacklisted bset (journal seq 0) in btree node at offset 0-8/32
  node offset 8/32 bset u64s 35 bset byte offset 120: keys out of order: u64s 5 type set 0:34359738397:0 len 2 ver 0 > u64s 5 type set 0:32:0 len 2 ver 0
  repair success (rewriting node)
bcachefs (loop0): btree node read error at btree backpointers level 0/0
  u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq 4a8b0fa43a9980a6 written 24 min_key POS_MIN durability: 1 ptr: 0:37:0 gen 0
  loop0 node offset 0/24 bset u64s 0: first btree node bset has blacklisted journal seq (0)
  loop0 node offset 0/24 bset u64s 0: found blacklisted bset (journal seq 0) in btree node at offset 0-8/24
  repair success (rewriting node)
bcachefs (loop0): check_topology...
bcachefs (loop0): btree root dirents unreadable, must recover from scan
bcachefs (loop0): no nodes found for btree dirents, continuing
bcachefs (loop0): btree root snapshots unreadable, must recover from scan
bcachefs (loop0): no nodes found for btree snapshots, continuing
 done
bcachefs (loop0): accounting_read... done
bcachefs (loop0): alloc_read... done
bcachefs (loop0): snapshots_read... done
bcachefs (loop0): check_allocations...
bcachefs (loop0): pointer to nonexistent device 1
bcachefs (loop0): pointer to missing device 1
  while marking u64s 7 type extent 4099:8:U32_MAX len 8 ver 0: durability: 0 crc: c_size 8 size 8 offset 0 nonce 0 csum none 0:0  compress incompressible ptr: 1:8704 gen 1, fixing
bcachefs (loop0): pointer to nonexistent device 1
bcachefs (loop0): bucket 0:34 data type user ptr gen 0 missing in alloc btree
  while marking u64s 7 type extent 536870913:24:U32_MAX len 24 ver 0: durability: 1 crc: c_size 8 size 24 offset 0 nonce 0 csum none 0:0  compress lz4 ptr: 0:34:8 gen 0, fixing
bcachefs (loop0): bucket 0:27 data type btree ptr gen 0 missing in alloc btree
  while marking u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq c6c25c03258c59c5 written 16 min_key POS_MIN durability: 1 ptr: 0:27:0 gen 0, fixing
bcachefs (loop0): bucket 0:38 data type btree ptr gen 0 missing in alloc btree
  while marking u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq 7589ab5e0c11cc7a written 24 min_key POS_MIN durability: 1 ptr: 0:38:0 gen 0, fixing
bcachefs (loop0): bucket 0:31 data type btree ptr gen 0 missing in alloc btree
  while marking u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq 2285c34bed0abe32 written 16 min_key POS_MIN durability: 1 ptr: 0:31:0 gen 0, fixing
bcachefs (loop0): bucket 0:35 data type btree ptr gen 0 missing in alloc btree
  while marking u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq c0bef60d07ceb940 written 16 min_key POS_MIN durability: 1 ptr: 0:35:0 gen 0, fixing
bcachefs (loop0): bucket 0:28 data type btree ptr gen 0 missing in alloc btree
  while marking u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq 28f61e078e70b95c written 16 min_key POS_MIN durability: 1 ptr: 0:28:0 gen 0, fixing
bcachefs (loop0): bucket 0:29 data type btree ptr gen 0 missing in alloc btree
  while marking u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq e81e1ed936acf3df written 32 min_key POS_MIN durability: 1 ptr: 0:29:0 gen 0, fixing
bcachefs (loop0): bucket 0:37 data type btree ptr gen 0 missing in alloc btree
  while marking u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq 4a8b0fa43a9980a6 written 24 min_key POS_MIN durability: 1 ptr: 0:37:0 gen 0, fixing
bcachefs (loop0): bucket 0:42 data type btree ptr gen 0 missing in alloc btree
  while marking u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq 1db8f60c84bb244c written 8 min_key POS_MIN durability: 1 ptr: 0:42:0 gen 0, fixing
 done
bcachefs (loop0): going read-write
bcachefs (loop0): journal_replay...
bcachefs (loop0): entry in freespace btree for nonexistant dev:bucket 0:33554475, fixing
bcachefs (loop0): entry in freespace btree for nonexistant dev:bucket 0:33554476, fixing
bcachefs (loop0): entry in freespace btree for nonexistant dev:bucket 0:33554477, fixing
==================================================================
BUG: KASAN: slab-use-after-free in bch2_bucket_alloc_trans+0x1aa0/0x2410 fs/bcachefs/alloc_foreground.c:547
Read of size 8 at addr ffff888054d7ca98 by task syz.0.0/5317

CPU: 0 UID: 0 PID: 5317 Comm: syz.0.0 Not tainted 6.16.0-rc3-syzkaller-00121-gf02769e7f272 #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
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xd2/0x2b0 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 bch2_bucket_alloc_trans+0x1aa0/0x2410 fs/bcachefs/alloc_foreground.c:547
 bch2_bucket_alloc_set_trans+0x5a6/0xe70 fs/bcachefs/alloc_foreground.c:728
 __open_bucket_add_buckets+0x1437/0x1e40 fs/bcachefs/alloc_foreground.c:925
 open_bucket_add_buckets+0x2ee/0x440 fs/bcachefs/alloc_foreground.c:957
 bch2_alloc_sectors_start_trans+0xd26/0x1e80 fs/bcachefs/alloc_foreground.c:-1
 __bch2_btree_node_alloc fs/bcachefs/btree_update_interior.c:320 [inline]
 bch2_btree_reserve_get+0x641/0x1810 fs/bcachefs/btree_update_interior.c:534
 bch2_btree_update_start+0x147e/0x1dc0 fs/bcachefs/btree_update_interior.c:1270
 bch2_btree_split_leaf+0x14b/0x8e0 fs/bcachefs/btree_update_interior.c:1920
 bch2_trans_commit_error+0x1b7/0x1130 fs/bcachefs/btree_trans_commit.c:911
 __bch2_trans_commit+0x1ce8/0x8880 fs/bcachefs/btree_trans_commit.c:1098
 bch2_trans_commit fs/bcachefs/btree_update.h:242 [inline]
 bch2_journal_replay+0x1789/0x2620 fs/bcachefs/recovery.c:396
 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:485 [inline]
 __bch2_run_recovery_passes+0x392/0x1010 fs/bcachefs/recovery_passes.c:540
 bch2_run_recovery_passes+0x184/0x210 fs/bcachefs/recovery_passes.c:611
 bch2_fs_recovery+0x25fd/0x3950 fs/bcachefs/recovery.c:989
 bch2_fs_start+0xa99/0xd90 fs/bcachefs/super.c:1203
 bch2_fs_get_tree+0xb02/0x14f0 fs/bcachefs/fs.c:2489
 vfs_get_tree+0x92/0x2b0 fs/super.c:1804
 do_new_mount+0x24a/0xa40 fs/namespace.c:3902
 do_mount fs/namespace.c:4239 [inline]
 __do_sys_mount fs/namespace.c:4450 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4427
 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: 0033:0x7f1df1b900ca
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f1df2941e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f1df2941ef0 RCX: 00007f1df1b900ca
RDX: 0000200000000000 RSI: 0000200000000040 RDI: 00007f1df2941eb0
RBP: 0000200000000000 R08: 00007f1df2941ef0 R09: 0000000000010000
R10: 0000000000010000 R11: 0000000000000246 R12: 0000200000000040
R13: 00007f1df2941eb0 R14: 000000000000593c R15: 0000200000005a80
 </TASK>

Allocated by task 5317:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4328 [inline]
 __kmalloc_node_track_caller_noprof+0x271/0x4e0 mm/slub.c:4347
 __do_krealloc mm/slub.c:4905 [inline]
 krealloc_noprof+0x124/0x340 mm/slub.c:4958
 __bch2_trans_kmalloc+0x26c/0xc80 fs/bcachefs/btree_iter.c:3187
 bch2_trans_kmalloc_nomemzero_ip fs/bcachefs/btree_iter.h:586 [inline]
 bch2_trans_kmalloc_nomemzero fs/bcachefs/btree_iter.h:621 [inline]
 bch2_alloc_sectors_start_trans+0x1d59/0x1e80 fs/bcachefs/alloc_foreground.c:1250
 __bch2_btree_node_alloc fs/bcachefs/btree_update_interior.c:320 [inline]
 bch2_btree_reserve_get+0x641/0x1810 fs/bcachefs/btree_update_interior.c:534
 bch2_btree_update_start+0x147e/0x1dc0 fs/bcachefs/btree_update_interior.c:1270
 bch2_btree_split_leaf+0x14b/0x8e0 fs/bcachefs/btree_update_interior.c:1920
 bch2_trans_commit_error+0x1b7/0x1130 fs/bcachefs/btree_trans_commit.c:911
 __bch2_trans_commit+0x1ce8/0x8880 fs/bcachefs/btree_trans_commit.c:1098
 bch2_trans_commit fs/bcachefs/btree_update.h:242 [inline]
 bch2_journal_replay+0x1789/0x2620 fs/bcachefs/recovery.c:396
 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:485 [inline]
 __bch2_run_recovery_passes+0x392/0x1010 fs/bcachefs/recovery_passes.c:540
 bch2_run_recovery_passes+0x184/0x210 fs/bcachefs/recovery_passes.c:611
 bch2_fs_recovery+0x25fd/0x3950 fs/bcachefs/recovery.c:989
 bch2_fs_start+0xa99/0xd90 fs/bcachefs/super.c:1203
 bch2_fs_get_tree+0xb02/0x14f0 fs/bcachefs/fs.c:2489
 vfs_get_tree+0x92/0x2b0 fs/super.c:1804
 do_new_mount+0x24a/0xa40 fs/namespace.c:3902
 do_mount fs/namespace.c:4239 [inline]
 __do_sys_mount fs/namespace.c:4450 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4427
 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

Freed by task 5317:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2381 [inline]
 slab_free mm/slub.c:4643 [inline]
 kfree+0x18e/0x440 mm/slub.c:4842
 krealloc_noprof+0x1cd/0x340 mm/slub.c:-1
 __bch2_trans_kmalloc+0x26c/0xc80 fs/bcachefs/btree_iter.c:3187
 bch2_trans_kmalloc_nomemzero_ip fs/bcachefs/btree_iter.h:586 [inline]
 bch2_trans_kmalloc_nomemzero fs/bcachefs/btree_iter.h:621 [inline]
 __bch2_trans_subbuf_alloc+0x2da/0x460 fs/bcachefs/btree_update.c:557
 bch2_trans_subbuf_alloc fs/bcachefs/btree_update.h:148 [inline]
 bch2_trans_jset_entry_alloc fs/bcachefs/btree_update.h:168 [inline]
 __bch2_trans_log_str fs/bcachefs/btree_update.c:814 [inline]
 bch2_trans_log_str+0xd5/0x3c0 fs/bcachefs/btree_update.c:827
 __bch2_fsck_err+0xc11/0xfb0 fs/bcachefs/error.c:625
 bch2_check_discard_freespace_key+0x569/0xce0 fs/bcachefs/alloc_background.c:1422
 try_alloc_bucket fs/bcachefs/alloc_foreground.c:272 [inline]
 bch2_bucket_alloc_freelist fs/bcachefs/alloc_foreground.c:420 [inline]
 bch2_bucket_alloc_trans+0x1333/0x2410 fs/bcachefs/alloc_foreground.c:544
 bch2_bucket_alloc_set_trans+0x5a6/0xe70 fs/bcachefs/alloc_foreground.c:728
 __open_bucket_add_buckets+0x1437/0x1e40 fs/bcachefs/alloc_foreground.c:925
 open_bucket_add_buckets+0x2ee/0x440 fs/bcachefs/alloc_foreground.c:957
 bch2_alloc_sectors_start_trans+0xd26/0x1e80 fs/bcachefs/alloc_foreground.c:-1
 __bch2_btree_node_alloc fs/bcachefs/btree_update_interior.c:320 [inline]
 bch2_btree_reserve_get+0x641/0x1810 fs/bcachefs/btree_update_interior.c:534
 bch2_btree_update_start+0x147e/0x1dc0 fs/bcachefs/btree_update_interior.c:1270
 bch2_btree_split_leaf+0x14b/0x8e0 fs/bcachefs/btree_update_interior.c:1920
 bch2_trans_commit_error+0x1b7/0x1130 fs/bcachefs/btree_trans_commit.c:911
 __bch2_trans_commit+0x1ce8/0x8880 fs/bcachefs/btree_trans_commit.c:1098
 bch2_trans_commit fs/bcachefs/btree_update.h:242 [inline]
 bch2_journal_replay+0x1789/0x2620 fs/bcachefs/recovery.c:396
 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:485 [inline]
 __bch2_run_recovery_passes+0x392/0x1010 fs/bcachefs/recovery_passes.c:540
 bch2_run_recovery_passes+0x184/0x210 fs/bcachefs/recovery_passes.c:611
 bch2_fs_recovery+0x25fd/0x3950 fs/bcachefs/recovery.c:989
 bch2_fs_start+0xa99/0xd90 fs/bcachefs/super.c:1203
 bch2_fs_get_tree+0xb02/0x14f0 fs/bcachefs/fs.c:2489
 vfs_get_tree+0x92/0x2b0 fs/super.c:1804
 do_new_mount+0x24a/0xa40 fs/namespace.c:3902
 do_mount fs/namespace.c:4239 [inline]
 __do_sys_mount fs/namespace.c:4450 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4427
 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

The buggy address belongs to the object at ffff888054d7c800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 664 bytes inside of
 freed 1024-byte region [ffff888054d7c800, ffff888054d7cc00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x54d7c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88801a441dc0 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 04fff00000000040 ffff88801a441dc0 dead000000000122 0000000000000000
head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 04fff00000000002 ffffea0001535f01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5317, tgid 5316 (syz.0.0), ts 75662029323, free_ts 75660278359
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704
 prep_new_page mm/page_alloc.c:1712 [inline]
 get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419
 alloc_slab_page mm/slub.c:2451 [inline]
 allocate_slab+0x8a/0x3b0 mm/slub.c:2619
 new_slab mm/slub.c:2673 [inline]
 ___slab_alloc+0xbfc/0x1480 mm/slub.c:3859
 __slab_alloc mm/slub.c:3949 [inline]
 __slab_alloc_node mm/slub.c:4024 [inline]
 slab_alloc_node mm/slub.c:4185 [inline]
 __do_kmalloc_node mm/slub.c:4327 [inline]
 __kmalloc_node_track_caller_noprof+0x2f8/0x4e0 mm/slub.c:4347
 __do_krealloc mm/slub.c:4905 [inline]
 krealloc_noprof+0x124/0x340 mm/slub.c:4958
 bch2_printbuf_make_room+0x1f5/0x360 fs/bcachefs/printbuf.c:59
 bch2_prt_printf+0x282/0x740 fs/bcachefs/printbuf.c:186
 __bch2_trans_paths_to_text+0xe5/0x190 fs/bcachefs/btree_iter.c:1589
 bch2_trans_update_max_paths+0x14e/0x340 fs/bcachefs/btree_iter.c:1625
 btree_path_alloc+0x89a/0xa70 fs/bcachefs/btree_iter.c:1722
 btree_path_clone fs/bcachefs/btree_iter.c:1262 [inline]
 __bch2_btree_path_make_mut+0x1cc/0x520 fs/bcachefs/btree_iter.c:1277
 bch2_btree_path_make_mut fs/bcachefs/btree_iter.h:217 [inline]
 __bch2_btree_path_set_pos+0x3f8/0x1530 fs/bcachefs/btree_iter.c:1295
 bch2_btree_path_set_pos fs/bcachefs/btree_iter.h:232 [inline]
 bch2_path_get+0xf82/0x1540 fs/bcachefs/btree_iter.c:1775
page last free pid 5317 tgid 5316 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1248 [inline]
 __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706
 stack_depot_save_flags+0x445/0x900 lib/stackdepot.c:678
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_save_track+0x4f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4328 [inline]
 __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4340
 mempool_alloc_noprof+0x1a7/0x510 mm/mempool.c:402
 bch2_btree_update_start+0x572/0x1dc0 fs/bcachefs/btree_update_interior.c:1219
 bch2_btree_split_leaf+0x14b/0x8e0 fs/bcachefs/btree_update_interior.c:1920
 bch2_trans_commit_error+0x1b7/0x1130 fs/bcachefs/btree_trans_commit.c:911
 __bch2_trans_commit+0x1ce8/0x8880 fs/bcachefs/btree_trans_commit.c:1098
 bch2_trans_commit fs/bcachefs/btree_update.h:242 [inline]
 bch2_journal_replay+0x1789/0x2620 fs/bcachefs/recovery.c:396
 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:485 [inline]
 __bch2_run_recovery_passes+0x392/0x1010 fs/bcachefs/recovery_passes.c:540
 bch2_run_recovery_passes+0x184/0x210 fs/bcachefs/recovery_passes.c:611
 bch2_fs_recovery+0x25fd/0x3950 fs/bcachefs/recovery.c:989
 bch2_fs_start+0xa99/0xd90 fs/bcachefs/super.c:1203
 bch2_fs_get_tree+0xb02/0x14f0 fs/bcachefs/fs.c:2489

Memory state around the buggy address:
 ffff888054d7c980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888054d7ca00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888054d7ca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888054d7cb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888054d7cb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================