================================================================== BUG: KASAN: slab-out-of-bounds in dtSplitPage+0x12c6/0x3b20 fs/jfs/jfs_dtree.c:-1 Read of size 1 at addr ffff88805025120d by task syz.0.306/8503 CPU: 1 UID: 0 PID: 8503 Comm: syz.0.306 Not tainted 6.16.0-rc3-syzkaller-00044-g7595b66ae9de #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 dtSplitPage+0x12c6/0x3b20 fs/jfs/jfs_dtree.c:-1 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline] dtInsert+0x109b/0x5f40 fs/jfs/jfs_dtree.c:871 jfs_mkdir+0x6ec/0xa70 fs/jfs/namei.c:270 vfs_mkdir+0x306/0x510 fs/namei.c:4375 do_mkdirat+0x247/0x590 fs/namei.c:4408 __do_sys_mkdirat fs/namei.c:4425 [inline] __se_sys_mkdirat fs/namei.c:4423 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4423 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: 0033:0x7fcde478e929 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:00007fcde5577038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fcde49b6160 RCX: 00007fcde478e929 RDX: 0000000000000040 RSI: 0000200000000340 RDI: ffffffffffffff9c RBP: 00007fcde4810b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fcde49b6160 R15: 00007fff922a9f78 Allocated by task 8502: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_lru_noprof+0x1c6/0x3d0 mm/slub.c:4216 jfs_alloc_inode+0x28/0x70 fs/jfs/super.c:105 alloc_inode+0x6a/0x1b0 fs/inode.c:346 iget_locked+0xf0/0x570 fs/inode.c:1439 jfs_iget+0x24/0x3e0 fs/jfs/inode.c:29 jfs_lookup+0x1c5/0x380 fs/jfs/namei.c:1469 __lookup_slow+0x294/0x3d0 fs/namei.c:1817 lookup_slow+0x53/0x70 fs/namei.c:1834 walk_component+0x2d2/0x400 fs/namei.c:2138 lookup_last fs/namei.c:2639 [inline] path_lookupat+0x163/0x430 fs/namei.c:2663 filename_lookup+0x212/0x570 fs/namei.c:2692 user_path_at+0x3a/0x60 fs/namei.c:3136 __do_sys_chdir fs/open.c:560 [inline] __se_sys_chdir+0x91/0x280 fs/open.c:554 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 The buggy address belongs to the object at ffff888050250938 which belongs to the cache jfs_ip of size 2232 The buggy address is located 29 bytes to the right of allocated 2232-byte region [ffff888050250938, ffff8880502511f0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888050252e18 pfn:0x50250 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888047b95601 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801dffe500 dead000000000122 0000000000000000 raw: ffff888050252e18 00000000800d0009 00000000f5000000 ffff888047b95601 head: 00fff00000000040 ffff88801dffe500 dead000000000122 0000000000000000 head: ffff888050252e18 00000000800d0009 00000000f5000000 ffff888047b95601 head: 00fff00000000003 ffffea0001409401 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Reclaimable, gfp_mask 0xd2050(__GFP_RECLAIMABLE|__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 7582, tgid 7581 (syz.4.187), ts 202601647513, free_ts 154822897289 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_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] kmem_cache_alloc_lru_noprof+0x288/0x3d0 mm/slub.c:4216 jfs_alloc_inode+0x28/0x70 fs/jfs/super.c:105 alloc_inode+0x6a/0x1b0 fs/inode.c:346 iget_locked+0xf0/0x570 fs/inode.c:1439 jfs_iget+0x24/0x3e0 fs/jfs/inode.c:29 jfs_lookup+0x1c5/0x380 fs/jfs/namei.c:1469 lookup_one_qstr_excl_raw+0x118/0x280 fs/namei.c:1689 lookup_one_qstr_excl fs/namei.c:1711 [inline] do_renameat2+0x401/0xc50 fs/namei.c:5238 __do_sys_rename fs/namei.c:5333 [inline] __se_sys_rename fs/namei.c:5331 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:5331 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 6883 tgid 6882 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_pages_ok+0xa3b/0xc10 mm/page_alloc.c:1424 __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+0x8f/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: ffff888050251100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888050251180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc >ffff888050251200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fa fb ^ ffff888050251280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888050251300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================