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 ffff888055088148 by task syz.0.0/5339 CPU: 0 UID: 0 PID: 5339 Comm: syz.0.0 Not tainted 6.15.0-rc1-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 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_sync_mmap_readahead+0x3e6/0x6c0 mm/filemap.c:-1 filemap_fault+0x763/0x13d0 mm/filemap.c:3402 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:rep_movs_alternative+0x30/0x90 arch/x86/lib/copy_user_64.S:60 Code: 83 f9 08 73 25 85 c9 74 0f 8a 06 88 07 48 ff c7 48 ff c6 48 ff c9 75 f1 c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 <48> 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08 RSP: 0018:ffffc900032bfd10 EFLAGS: 00050246 RAX: 00007ffffffff001 RBX: 0000200000000080 RCX: 0000000000000008 RDX: 0000000000000001 RSI: 0000200000000080 RDI: ffff88803601a8c0 RBP: ffff88803601a8c0 R08: ffff88803601a8c7 R09: 1ffff11006c03518 R10: dffffc0000000000 R11: ffffed1006c03519 R12: 0000000000000002 R13: 0000000000000008 R14: ffff88803601a8c0 R15: 0000000000000008 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:141 [inline] _inline_copy_from_user include/linux/uaccess.h:178 [inline] _copy_from_user+0x7b/0xb0 lib/usercopy.c:18 copy_from_user include/linux/uaccess.h:212 [inline] copy_from_sockptr_offset include/linux/sockptr.h:48 [inline] copy_from_sockptr include/linux/sockptr.h:61 [inline] memdup_sockptr_noprof include/linux/sockptr.h:130 [inline] sctp_setsockopt+0xc9/0x11e0 net/sctp/socket.c:4595 do_sock_setsockopt+0x3b1/0x710 net/socket.c:2296 __sys_setsockopt net/socket.c:2321 [inline] __do_sys_setsockopt net/socket.c:2327 [inline] __se_sys_setsockopt net/socket.c:2324 [inline] __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2324 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: 0033:0x7f5d3598d169 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:00007f5d368b3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f5d35ba5fa0 RCX: 00007f5d3598d169 RDX: 0000000000000002 RSI: 0000000000000084 RDI: 0000000000000004 RBP: 00007f5d368b3090 R08: 0000000000000008 R09: 0000000000000000 R10: 0000200000000080 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 00007f5d35ba5fa0 R15: 00007ffde56ff5e8 Allocated by task 5339: 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_sync_mmap_readahead+0x3e6/0x6c0 mm/filemap.c:-1 filemap_fault+0x763/0x13d0 mm/filemap.c:3402 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 5339: 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_sync_mmap_readahead+0x3e6/0x6c0 mm/filemap.c:-1 filemap_fault+0x763/0x13d0 mm/filemap.c:3402 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 ffff888055088000 which belongs to the cache bio-488 of size 488 The buggy address is located 328 bytes inside of freed 488-byte region [ffff888055088000, ffff8880550881e8) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x55088 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 ffff888055075000 dead000000000122 0000000000000000 raw: 0000000000000000 00000000800c000c 00000000f5000000 0000000000000000 head: 04fff00000000040 ffff888055075000 dead000000000122 0000000000000000 head: 0000000000000000 00000000800c000c 00000000f5000000 0000000000000000 head: 04fff00000000001 ffffea0001542201 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 5339, tgid 5338 (syz.0.0), ts 149104701456, free_ts 0 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_owner free stack trace missing Memory state around the buggy address: ffff888055088000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888055088080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888055088100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888055088180: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff888055088200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 83 f9 08 cmp $0x8,%ecx 3: 73 25 jae 0x2a 5: 85 c9 test %ecx,%ecx 7: 74 0f je 0x18 9: 8a 06 mov (%rsi),%al b: 88 07 mov %al,(%rdi) d: 48 ff c7 inc %rdi 10: 48 ff c6 inc %rsi 13: 48 ff c9 dec %rcx 16: 75 f1 jne 0x9 18: c3 ret 19: cc int3 1a: cc int3 1b: cc int3 1c: cc int3 1d: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 24: 00 00 00 27: 0f 1f 00 nopl (%rax) * 2a: 48 8b 06 mov (%rsi),%rax <-- trapping instruction 2d: 48 89 07 mov %rax,(%rdi) 30: 48 83 c6 08 add $0x8,%rsi 34: 48 83 c7 08 add $0x8,%rdi 38: 83 e9 08 sub $0x8,%ecx 3b: 74 db je 0x18 3d: 83 f9 08 cmp $0x8,%ecx