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+0x2ac0/0x3290 fs/bcachefs/fs-io-buffered.c:228 Read of size 4 at addr ffff888043d80148 by task syz.0.0/5321 CPU: 0 UID: 0 PID: 5321 Comm: syz.0.0 Not tainted 6.15.0-rc1-syzkaller-00065-g3b07108ada81 #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: __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+0x2ac0/0x3290 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 do_async_mmap_readahead mm/filemap.c:3289 [inline] filemap_fault+0x6ce/0x13d0 mm/filemap.c:3388 bch2_page_fault+0x52e/0x960 fs/bcachefs/fs-io-pagecache.c:594 __do_fault+0x135/0x390 mm/memory.c:5098 do_read_fault mm/memory.c:5518 [inline] do_fault mm/memory.c:5652 [inline] do_pte_missing mm/memory.c:4160 [inline] handle_pte_fault+0x3f0c/0x61c0 mm/memory.c:5997 __handle_mm_fault mm/memory.c:6140 [inline] handle_mm_fault+0x1129/0x1bf0 mm/memory.c:6309 do_user_addr_fault arch/x86/mm/fault.c:1388 [inline] handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x2bb/0x920 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:fault_in_readable+0x177/0x2e0 mm/gup.c:2241 Code: 49 81 c5 ff 0f 00 00 49 81 e5 00 f0 ff ff 49 39 c5 0f 82 85 00 00 00 e8 e7 07 b3 ff 4c 39 eb 0f 84 88 00 00 00 4c 89 64 24 10 <44> 8a 23 43 0f b6 04 3e 84 c0 75 18 44 88 64 24 40 48 81 c3 00 10 RSP: 0018:ffffc9000d427900 EFLAGS: 00050246 RAX: ffffffff82105db9 RBX: 00002000005a0000 RCX: 0000000000100000 RDX: ffffc9000dff2000 RSI: 00000000000fffff RDI: 0000000000100000 RBP: ffffc9000d4279b8 R08: ffffffff82105d20 R09: ffffffff85026549 R10: 0000000000000002 R11: ffff888000ea4880 R12: 000000000208e200 R13: 000020000208f000 R14: 1ffff92001a84f28 R15: dffffc0000000000 fault_in_iov_iter_readable+0x229/0x280 lib/iov_iter.c:94 bch2_buffered_write fs/bcachefs/fs-io-buffered.c:1004 [inline] bch2_write_iter+0x5b2/0x2cd0 fs/bcachefs/fs-io-buffered.c:1075 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x70f/0xd10 fs/read_write.c:684 ksys_write+0x19d/0x2d0 fs/read_write.c:736 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: 0033:0x7f02cd18d169 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:00007f02cdff3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f02cd3a5fa0 RCX: 00007f02cd18d169 RDX: 000000000208e24b RSI: 0000200000000000 RDI: 0000000000000007 RBP: 00007f02cd20e730 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f02cd3a5fa0 R15: 00007ffe80332d18 Allocated by task 5321: 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 do_async_mmap_readahead mm/filemap.c:3289 [inline] filemap_fault+0x6ce/0x13d0 mm/filemap.c:3388 bch2_page_fault+0x52e/0x960 fs/bcachefs/fs-io-pagecache.c:594 __do_fault+0x135/0x390 mm/memory.c:5098 do_read_fault mm/memory.c:5518 [inline] do_fault mm/memory.c:5652 [inline] do_pte_missing mm/memory.c:4160 [inline] handle_pte_fault+0x3f0c/0x61c0 mm/memory.c:5997 __handle_mm_fault mm/memory.c:6140 [inline] handle_mm_fault+0x1129/0x1bf0 mm/memory.c:6309 do_user_addr_fault arch/x86/mm/fault.c:1388 [inline] handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x2bb/0x920 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 Freed by task 5321: 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+0x2379/0x3290 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 do_async_mmap_readahead mm/filemap.c:3289 [inline] filemap_fault+0x6ce/0x13d0 mm/filemap.c:3388 bch2_page_fault+0x52e/0x960 fs/bcachefs/fs-io-pagecache.c:594 __do_fault+0x135/0x390 mm/memory.c:5098 do_read_fault mm/memory.c:5518 [inline] do_fault mm/memory.c:5652 [inline] do_pte_missing mm/memory.c:4160 [inline] handle_pte_fault+0x3f0c/0x61c0 mm/memory.c:5997 __handle_mm_fault mm/memory.c:6140 [inline] handle_mm_fault+0x1129/0x1bf0 mm/memory.c:6309 do_user_addr_fault arch/x86/mm/fault.c:1388 [inline] handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x2bb/0x920 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 The buggy address belongs to the object at ffff888043d80000 which belongs to the cache bio-488 of size 488 The buggy address is located 328 bytes inside of freed 488-byte region [ffff888043d80000, ffff888043d801e8) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x43d80 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 ffff888040720280 dead000000000122 0000000000000000 raw: 0000000000000000 00000000000c000c 00000000f5000000 0000000000000000 head: 04fff00000000040 ffff888040720280 dead000000000122 0000000000000000 head: 0000000000000000 00000000000c000c 00000000f5000000 0000000000000000 head: 04fff00000000001 ffffea00010f6001 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 5321, tgid 5320 (syz.0.0), ts 68115461165, free_ts 68098218394 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:953 [inline] bch2_fs_open+0x2f37/0x32a0 fs/bcachefs/super.c:2219 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:3879 page last free pid 5321 tgid 5320 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 __slab_free+0x2c6/0x390 mm/slub.c:4557 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4151 [inline] slab_alloc_node mm/slub.c:4200 [inline] __do_kmalloc_node mm/slub.c:4330 [inline] __kmalloc_node_track_caller_noprof+0x23a/0x4d0 mm/slub.c:4350 kvasprintf+0xe1/0x190 lib/kasprintf.c:25 kasprintf+0xd7/0x120 lib/kasprintf.c:59 wq_init_lockdep kernel/workqueue.c:4802 [inline] alloc_workqueue+0x123/0x210 kernel/workqueue.c:5791 bch2_fs_journal_init+0x62c/0x830 fs/bcachefs/journal.c:1596 bch2_fs_alloc fs/bcachefs/super.c:944 [inline] bch2_fs_open+0x2d41/0x32a0 fs/bcachefs/super.c:2219 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:3879 do_mount fs/namespace.c:4219 [inline] __do_sys_mount fs/namespace.c:4430 [inline] __se_sys_mount+0x38c/0x400 fs/namespace.c:4407 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 Memory state around the buggy address: ffff888043d80000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888043d80080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888043d80100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888043d80180: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff888043d80200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 49 81 c5 ff 0f 00 00 add $0xfff,%r13 7: 49 81 e5 00 f0 ff ff and $0xfffffffffffff000,%r13 e: 49 39 c5 cmp %rax,%r13 11: 0f 82 85 00 00 00 jb 0x9c 17: e8 e7 07 b3 ff call 0xffb30803 1c: 4c 39 eb cmp %r13,%rbx 1f: 0f 84 88 00 00 00 je 0xad 25: 4c 89 64 24 10 mov %r12,0x10(%rsp) * 2a: 44 8a 23 mov (%rbx),%r12b <-- trapping instruction 2d: 43 0f b6 04 3e movzbl (%r14,%r15,1),%eax 32: 84 c0 test %al,%al 34: 75 18 jne 0x4e 36: 44 88 64 24 40 mov %r12b,0x40(%rsp) 3b: 48 rex.W 3c: 81 .byte 0x81 3d: c3 ret 3e: 00 10 add %dl,(%rax)