bcachefs (loop0): Detected missing backpointers in bucket 34, now have 1/128 with missing running recovery pass check_extents_to_backpointers (17), currently at resume_logged_ops (39) bcachefs (loop0): Detected missing backpointers in bucket 34, now have 1/128 with missing running recovery pass check_extents_to_backpointers (17), currently at check_extents_to_backpointers (17) ================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: slab-use-after-free in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] BUG: KASAN: slab-use-after-free in bch2_bucket_bitmap_test fs/bcachefs/backpointers.h:194 [inline] BUG: KASAN: slab-use-after-free in bch2_bucket_is_movable fs/bcachefs/movinggc.c:78 [inline] BUG: KASAN: slab-use-after-free in bch2_copygc_get_buckets fs/bcachefs/movinggc.c:157 [inline] BUG: KASAN: slab-use-after-free in bch2_copygc+0x105d/0x4510 fs/bcachefs/movinggc.c:221 Read of size 8 at addr ffff888055ae5760 by task bch-copygc/loop/5348 CPU: 0 UID: 0 PID: 5348 Comm: bch-copygc/loop Not tainted 6.16.0-rc7-syzkaller-00127-g302f88ff3584 #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_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] bch2_bucket_bitmap_test fs/bcachefs/backpointers.h:194 [inline] bch2_bucket_is_movable fs/bcachefs/movinggc.c:78 [inline] bch2_copygc_get_buckets fs/bcachefs/movinggc.c:157 [inline] bch2_copygc+0x105d/0x4510 fs/bcachefs/movinggc.c:221 bch2_copygc_thread+0x97a/0xe00 fs/bcachefs/movinggc.c:409 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 5348: 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] __kvmalloc_node_noprof+0x30d/0x5f0 mm/slub.c:5015 kvmalloc_array_node_noprof include/linux/slab.h:1065 [inline] bch2_bucket_bitmap_set+0x9a/0x1a0 fs/bcachefs/backpointers.c:1351 check_bucket_backpointer_mismatch+0x1bdf/0x23a0 fs/bcachefs/backpointers.c:964 check_bucket_backpointer_pos_mismatch fs/bcachefs/backpointers.c:1193 [inline] bch2_check_bucket_backpointer_mismatch+0x36c/0x690 fs/bcachefs/backpointers.c:1205 __bch2_move_data_phys+0x17a7/0x1c50 fs/bcachefs/move.c:922 bch2_evacuate_bucket+0x228/0x3a0 fs/bcachefs/move.c:1082 bch2_copygc+0x3be3/0x4510 fs/bcachefs/movinggc.c:234 bch2_copygc_thread+0x97a/0xe00 fs/bcachefs/movinggc.c:409 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff888055ae5760 which belongs to the cache kmalloc-16 of size 16 The buggy address is located 0 bytes inside of freed 16-byte region [ffff888055ae5760, ffff888055ae5770) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x55ae5 flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000000 ffff88801a441640 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080800080 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5338, tgid 5337 (syz.0.0), ts 75463285066, free_ts 0 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 prt_bytes fs/bcachefs/printbuf.h:227 [inline] prt_str+0x3e/0x760 fs/bcachefs/printbuf.h:239 bch2_btree_node_read_done+0x6b5/0x5550 fs/bcachefs/btree_io.c:1095 btree_node_read_work+0x40e/0xe60 fs/bcachefs/btree_io.c:1440 bch2_btree_node_read+0x887/0x2a00 fs/bcachefs/btree_io.c:-1 __bch2_btree_root_read fs/bcachefs/btree_io.c:1906 [inline] bch2_btree_root_read+0x5f0/0x760 fs/bcachefs/btree_io.c:1928 read_btree_roots+0x2c6/0x840 fs/bcachefs/recovery.c:615 bch2_fs_recovery+0x261f/0x3a50 fs/bcachefs/recovery.c:1006 page_owner free stack trace missing Memory state around the buggy address: ffff888055ae5600: fa fb fc fc fa fb fc fc 00 00 fc fc fa fb fc fc ffff888055ae5680: fa fb fc fc 00 00 fc fc fa fb fc fc fa fb fc fc >ffff888055ae5700: 00 00 fc fc fa fb fc fc fa fb fc fc fb fb fc fc ^ ffff888055ae5780: 00 00 fc fc fa fb fc fc fa fb fc fc 00 00 fc fc ffff888055ae5800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================