loop0: detected capacity change from 0 to 32768
bcachefs (loop0): starting version 1.7: mi_btree_bitmap opts=errors=continue,metadata_checksum=none,data_checksum=none,compression=lz4,nojournal_transaction_names
bcachefs (loop0): initializing new filesystem
bcachefs (loop0): going read-write
bcachefs (loop0): marking superblocks
bcachefs (loop0): initializing freespace
bcachefs (loop0): done initializing freespace
bcachefs (loop0): reading snapshots table
bcachefs (loop0): reading snapshots done
bcachefs (loop0): done starting filesystem
==================================================================
BUG: KASAN: slab-use-after-free in bchfs_read+0x2b48/0x3350 fs/bcachefs/fs-io-buffered.c:228
Read of size 4 at addr ffff888042978148 by task syz.0.0/5323

CPU: 0 UID: 0 PID: 5323 Comm: syz.0.0 Not tainted 6.14.0-syzkaller-12245-g91e5bfe317d8 #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 lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0x16e/0x5b0 mm/kasan/report.c:521
 kasan_report+0x143/0x180 mm/kasan/report.c:634
 bchfs_read+0x2b48/0x3350 fs/bcachefs/fs-io-buffered.c:228
 bch2_readahead+0xe7a/0x12d0 fs/bcachefs/fs-io-buffered.c:301
 read_pages+0x193/0x590 mm/readahead.c:160
 page_cache_ra_order+0xa37/0xca0 mm/readahead.c:515
 filemap_readahead mm/filemap.c:2559 [inline]
 filemap_get_pages+0x9ec/0x1fc0 mm/filemap.c:2604
 filemap_read+0x466/0x1260 mm/filemap.c:2701
 bch2_read_iter+0x1179/0x14b0 fs/bcachefs/fs-io-direct.c:221
 __kernel_read+0x532/0xa10 fs/read_write.c:528
 integrity_kernel_read+0xb2/0x100 security/integrity/iint.c:28
 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:480 [inline]
 ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline]
 ima_calc_file_hash+0xb22/0x1c10 security/integrity/ima/ima_crypto.c:568
 ima_collect_measurement+0x52b/0xb20 security/integrity/ima/ima_api.c:293
 process_measurement+0x13a3/0x1fe0 security/integrity/ima/ima_main.c:383
 ima_file_check+0xdb/0x130 security/integrity/ima/ima_main.c:611
 security_file_post_open+0xb9/0x280 security/security.c:3130
 do_open fs/namei.c:3847 [inline]
 path_openat+0x2cf7/0x35d0 fs/namei.c:4004
 do_filp_open+0x284/0x4e0 fs/namei.c:4031
 do_sys_openat2+0x12b/0x1d0 fs/open.c:1429
 do_sys_open fs/open.c:1444 [inline]
 __do_sys_open fs/open.c:1452 [inline]
 __se_sys_open fs/open.c:1448 [inline]
 __x64_sys_open+0x226/0x280 fs/open.c:1448
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f12fb58d169
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:00007f12fc359038 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f12fb7a5fa0 RCX: 00007f12fb58d169
RDX: 0000000000000000 RSI: 0000000000060142 RDI: 0000200000000000
RBP: 00007f12fb60e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f12fb7a5fa0 R15: 00007fffbc8ddb18
 </TASK>

Allocated by task 5323:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_mempool_unpoison_object+0x9e/0x170 mm/kasan/common.c:547
 kasan_unpoison_element mm/mempool.c:-1 [inline]
 remove_element+0x129/0x1a0 mm/mempool.c:150
 mempool_alloc_noprof+0x552/0x5a0 mm/mempool.c:408
 bio_alloc_bioset+0x26f/0x1130 block/bio.c:554
 bch2_readahead+0xbaf/0x12d0 fs/bcachefs/fs-io-buffered.c:290
 read_pages+0x193/0x590 mm/readahead.c:160
 page_cache_ra_order+0xa37/0xca0 mm/readahead.c:515
 filemap_readahead mm/filemap.c:2559 [inline]
 filemap_get_pages+0x9ec/0x1fc0 mm/filemap.c:2604
 filemap_read+0x466/0x1260 mm/filemap.c:2701
 bch2_read_iter+0x1179/0x14b0 fs/bcachefs/fs-io-direct.c:221
 __kernel_read+0x532/0xa10 fs/read_write.c:528
 integrity_kernel_read+0xb2/0x100 security/integrity/iint.c:28
 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:480 [inline]
 ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline]
 ima_calc_file_hash+0xb22/0x1c10 security/integrity/ima/ima_crypto.c:568
 ima_collect_measurement+0x52b/0xb20 security/integrity/ima/ima_api.c:293
 process_measurement+0x13a3/0x1fe0 security/integrity/ima/ima_main.c:383
 ima_file_check+0xdb/0x130 security/integrity/ima/ima_main.c:611
 security_file_post_open+0xb9/0x280 security/security.c:3130
 do_open fs/namei.c:3847 [inline]
 path_openat+0x2cf7/0x35d0 fs/namei.c:4004
 do_filp_open+0x284/0x4e0 fs/namei.c:4031
 do_sys_openat2+0x12b/0x1d0 fs/open.c:1429
 do_sys_open fs/open.c:1444 [inline]
 __do_sys_open fs/open.c:1452 [inline]
 __se_sys_open fs/open.c:1448 [inline]
 __x64_sys_open+0x226/0x280 fs/open.c:1448
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5323:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_mempool_poison_object+0xaa/0x120 mm/kasan/common.c:522
 kasan_mempool_poison_object include/linux/kasan.h:360 [inline]
 kasan_poison_element mm/mempool.c:118 [inline]
 add_element mm/mempool.c:141 [inline]
 mempool_free+0x1c8/0x390 mm/mempool.c:541
 bch2_readpages_end_io+0x17c/0x1d0 fs/bcachefs/fs-io-buffered.c:36
 bch2_rbio_done fs/bcachefs/io_read.c:430 [inline]
 __bch2_read_extent+0x1348/0x4400 fs/bcachefs/io_read.c:1257
 bch2_read_extent fs/bcachefs/io_read.h:140 [inline]
 bchfs_read+0x251a/0x3350 fs/bcachefs/fs-io-buffered.c:226
 bch2_readahead+0xe7a/0x12d0 fs/bcachefs/fs-io-buffered.c:301
 read_pages+0x193/0x590 mm/readahead.c:160
 page_cache_ra_order+0xa37/0xca0 mm/readahead.c:515
 filemap_readahead mm/filemap.c:2559 [inline]
 filemap_get_pages+0x9ec/0x1fc0 mm/filemap.c:2604
 filemap_read+0x466/0x1260 mm/filemap.c:2701
 bch2_read_iter+0x1179/0x14b0 fs/bcachefs/fs-io-direct.c:221
 __kernel_read+0x532/0xa10 fs/read_write.c:528
 integrity_kernel_read+0xb2/0x100 security/integrity/iint.c:28
 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:480 [inline]
 ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline]
 ima_calc_file_hash+0xb22/0x1c10 security/integrity/ima/ima_crypto.c:568
 ima_collect_measurement+0x52b/0xb20 security/integrity/ima/ima_api.c:293
 process_measurement+0x13a3/0x1fe0 security/integrity/ima/ima_main.c:383
 ima_file_check+0xdb/0x130 security/integrity/ima/ima_main.c:611
 security_file_post_open+0xb9/0x280 security/security.c:3130
 do_open fs/namei.c:3847 [inline]
 path_openat+0x2cf7/0x35d0 fs/namei.c:4004
 do_filp_open+0x284/0x4e0 fs/namei.c:4031
 do_sys_openat2+0x12b/0x1d0 fs/open.c:1429
 do_sys_open fs/open.c:1444 [inline]
 __do_sys_open fs/open.c:1452 [inline]
 __se_sys_open fs/open.c:1448 [inline]
 __x64_sys_open+0x226/0x280 fs/open.c:1448
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888042978000
 which belongs to the cache bio-488 of size 488
The buggy address is located 328 bytes inside of
 freed 488-byte region [ffff888042978000, ffff8880429781e8)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x42978
head: order:1 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 ffff888036daf280 dead000000000122 0000000000000000
raw: 0000000000000000 00000000000c000c 00000000f5000000 0000000000000000
head: 04fff00000000040 ffff888036daf280 dead000000000122 0000000000000000
head: 0000000000000000 00000000000c000c 00000000f5000000 0000000000000000
head: 04fff00000000001 ffffea00010a5e01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5323, tgid 5322 (syz.0.0), ts 79162189235, free_ts 78905640026
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1717
 prep_new_page mm/page_alloc.c:1725 [inline]
 get_page_from_freelist+0x352b/0x36c0 mm/page_alloc.c:3652
 __alloc_frozen_pages_noprof+0x211/0x5b0 mm/page_alloc.c:4934
 alloc_pages_mpol+0x339/0x690 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2459 [inline]
 allocate_slab+0x8f/0x3a0 mm/slub.c:2623
 new_slab mm/slub.c:2676 [inline]
 ___slab_alloc+0xc3b/0x1500 mm/slub.c:3862
 __slab_alloc+0x58/0xa0 mm/slub.c:3952
 __slab_alloc_node mm/slub.c:4027 [inline]
 slab_alloc_node mm/slub.c:4188 [inline]
 kmem_cache_alloc_noprof+0x270/0x390 mm/slub.c:4207
 mempool_init_node+0x1ee/0x4e0 mm/mempool.c:217
 mempool_init_noprof+0x3a/0x50 mm/mempool.c:246
 bioset_init+0x2ea/0x820 block/bio.c:1709
 bch2_fs_io_read_init+0x29/0xc0 fs/bcachefs/io_read.c:1377
 bch2_fs_alloc fs/bcachefs/super.c:944 [inline]
 bch2_fs_open+0x2f2f/0x32a0 fs/bcachefs/super.c:2182
 bch2_fs_get_tree+0x77b/0x18f0 fs/bcachefs/fs.c:2172
 vfs_get_tree+0x90/0x2b0 fs/super.c:1759
 do_new_mount+0x2cf/0xb70 fs/namespace.c:3878
page last free pid 4728 tgid 4728 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1262 [inline]
 __free_frozen_pages+0xde8/0x10a0 mm/page_alloc.c:2680
 mm_free_pgd kernel/fork.c:793 [inline]
 __mmdrop+0xb9/0x490 kernel/fork.c:939
 mmdrop include/linux/sched/mm.h:55 [inline]
 mmdrop_sched include/linux/sched/mm.h:83 [inline]
 mmdrop_lazy_tlb_sched include/linux/sched/mm.h:110 [inline]
 finish_task_switch+0x304/0x870 kernel/sched/core.c:5275
 context_switch kernel/sched/core.c:5385 [inline]
 __schedule+0x1b90/0x5240 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x163/0x360 kernel/sched/core.c:6860
 schedule_hrtimeout_range_clock+0x193/0x360 kernel/time/sleep_timeout.c:216
 ep_poll fs/eventpoll.c:2107 [inline]
 do_epoll_wait+0xe2c/0x1100 fs/eventpoll.c:2523
 __do_sys_epoll_wait fs/eventpoll.c:2531 [inline]
 __se_sys_epoll_wait fs/eventpoll.c:2526 [inline]
 __x64_sys_epoll_wait+0x259/0x2b0 fs/eventpoll.c:2526
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888042978000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888042978080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888042978100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff888042978180: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
 ffff888042978200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================