bcachefs (loop0): btree node read error at btree dirents level 0/0 u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq 9aa2895aefce4bdf written 24 min_key POS_MIN durability: 1 ptr: 0:41:0 gen 0 loop0 node offset 16/24: btree node data missing: expected 24 sectors, found 16 repair success (rewriting node) ================================================================== BUG: KASAN: use-after-free in bch2_btree_node_read_done+0xd3b/0x51f0 fs/bcachefs/btree_io.c:1138 Read of size 8 at addr ffff8880606f8010 by task syz.0.15/6553 CPU: 1 UID: 0 PID: 6553 Comm: syz.0.15 Not tainted 6.16.0-rc3-syzkaller-g86731a2a651e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: 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_btree_node_read_done+0xd3b/0x51f0 fs/bcachefs/btree_io.c:1138 btree_node_read_work+0x426/0xe30 fs/bcachefs/btree_io.c:1411 bch2_btree_node_read+0x887/0x2a00 fs/bcachefs/btree_io.c:-1 __bch2_btree_root_read fs/bcachefs/btree_io.c:1877 [inline] bch2_btree_root_read+0x5f0/0x760 fs/bcachefs/btree_io.c:1899 read_btree_roots+0x2c2/0x880 fs/bcachefs/recovery.c:604 bch2_fs_recovery+0x2574/0x3950 fs/bcachefs/recovery.c:979 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:3885 do_mount fs/namespace.c:4222 [inline] __do_sys_mount fs/namespace.c:4433 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4410 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: 0033:0x7fc43917ffba 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:00007fc43a008e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fc43a008ef0 RCX: 00007fc43917ffba RDX: 00000000200000c0 RSI: 0000000020000180 RDI: 00007fc43a008eb0 RBP: 00000000200000c0 R08: 00007fc43a008ef0 R09: 0000000000000010 R10: 0000000000000010 R11: 0000000000000246 R12: 0000000020000180 R13: 00007fc43a008eb0 R14: 0000000000005943 R15: 0000000020000480 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x606f8 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea000181c008 ffff8880b873fc60 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 2, migratetype Reclaimable, gfp_mask 0x4428d0(GFP_NOWAIT|__GFP_RECLAIMABLE|__GFP_IO|__GFP_FS|__GFP_COMP|__GFP_ACCOUNT), pid 6553, tgid 6552 (syz.0.15), ts 127902158270, free_ts 128205182493 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+0x21d5/0x22b0 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959 __alloc_pages_noprof+0xa/0x30 mm/page_alloc.c:4993 __alloc_pages_node_noprof include/linux/gfp.h:284 [inline] alloc_pages_node_noprof include/linux/gfp.h:311 [inline] ___kmalloc_large_node+0x85/0x210 mm/slub.c:4272 __kmalloc_large_node_noprof+0x18/0x90 mm/slub.c:4300 __do_kmalloc_node mm/slub.c:4316 [inline] __kvmalloc_node_noprof+0x6d/0x5f0 mm/slub.c:5015 btree_node_data_alloc+0xdc/0x270 fs/bcachefs/btree_cache.c:150 __bch2_btree_node_mem_alloc+0x1ef/0x420 fs/bcachefs/btree_cache.c:195 bch2_fs_btree_cache_init+0x2de/0x690 fs/bcachefs/btree_cache.c:656 bch2_fs_alloc fs/bcachefs/super.c:999 [inline] bch2_fs_open+0x1ceb/0x2570 fs/bcachefs/super.c:2423 bch2_fs_get_tree+0x437/0x14f0 fs/bcachefs/fs.c:2473 vfs_get_tree+0x92/0x2b0 fs/super.c:1804 do_new_mount+0x24a/0xa40 fs/namespace.c:3885 do_mount fs/namespace.c:4222 [inline] __do_sys_mount fs/namespace.c:4433 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4410 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 page last free pid 6553 tgid 6552 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc65/0xe60 mm/page_alloc.c:2706 __folio_put+0x21b/0x2c0 mm/swap.c:112 folio_put include/linux/mm.h:1356 [inline] free_large_kmalloc+0x145/0x200 mm/slub.c:4768 btree_bounce_free fs/bcachefs/btree_io.c:115 [inline] bch2_btree_node_read_done+0x329a/0x51f0 fs/bcachefs/btree_io.c:1294 btree_node_read_work+0x426/0xe30 fs/bcachefs/btree_io.c:1411 bch2_btree_node_read+0x887/0x2a00 fs/bcachefs/btree_io.c:-1 __bch2_btree_root_read fs/bcachefs/btree_io.c:1877 [inline] bch2_btree_root_read+0x5f0/0x760 fs/bcachefs/btree_io.c:1899 read_btree_roots+0x2c2/0x880 fs/bcachefs/recovery.c:604 bch2_fs_recovery+0x2574/0x3950 fs/bcachefs/recovery.c:979 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:3885 do_mount fs/namespace.c:4222 [inline] __do_sys_mount fs/namespace.c:4433 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4410 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 Memory state around the buggy address: ffff8880606f7f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880606f7f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880606f8000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8880606f8080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880606f8100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================