ERROR: (device loop4): dtSearch: stack overrun! ERROR: (device loop4): remounting filesystem as read-only btstack dump: bn = 0, index = 0 bn = 72c, index = 96 bn = 0, index = 0 bn = 72c, index = 96 bn = 0, index = 0 bn = 72c, index = 96 bn = 0, index = 0 bn = 0, index = 0 ================================================================== ================================================================== BUG: KASAN: slab-use-after-free in drop_metapage fs/jfs/jfs_metapage.c:311 [inline] BUG: KASAN: slab-use-after-free in release_metapage+0x753/0xab0 fs/jfs/jfs_metapage.c:892 Read of size 8 at addr ffff88803b8169e8 by task syz.4.47/6196 CPU: 0 UID: 0 PID: 6196 Comm: syz.4.47 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 drop_metapage fs/jfs/jfs_metapage.c:311 [inline] release_metapage+0x753/0xab0 fs/jfs/jfs_metapage.c:892 dtSearch+0x1c4e/0x21b0 fs/jfs/jfs_dtree.c:793 jfs_symlink+0x857/0xfd0 fs/jfs/namei.c:1018 vfs_symlink+0x195/0x340 fs/namei.c:5621 filename_symlinkat+0x1cd/0x420 fs/namei.c:5646 __do_sys_symlink fs/namei.c:5673 [inline] __se_sys_symlink+0x4d/0x2b0 fs/namei.c:5669 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9eea85c819 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9ee8a95028 EFLAGS: 00000246 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 00007f9eeaad6090 RCX: 00007f9eea85c819 RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000200000001640 RBP: 00007f9eea8f2c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9eeaad6128 R14: 00007f9eeaad6090 R15: 00007ffd8b5eb028 Allocated by task 6177: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4873 mempool_alloc_noprof+0x1d4/0x300 mm/mempool.c:566 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline] __get_metapage+0x50c/0xde0 fs/jfs/jfs_metapage.c:760 dtSplitRoot+0x202/0x16c0 fs/jfs/jfs_dtree.c:1910 dtSplitUp fs/jfs/jfs_dtree.c:993 [inline] dtInsert+0xf19/0x5f10 fs/jfs/jfs_dtree.c:871 jfs_rename+0x89d/0x1860 fs/jfs/namei.c:1226 vfs_rename+0xa96/0xeb0 fs/namei.c:6032 filename_renameat2+0x539/0x9c0 fs/namei.c:6150 __do_sys_rename fs/namei.c:6194 [inline] __se_sys_rename+0x55/0x2c0 fs/namei.c:6190 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6177: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2685 [inline] slab_free mm/slub.c:6165 [inline] kmem_cache_free+0x185/0x6b0 mm/slub.c:6295 mempool_free+0xf5/0x140 mm/mempool.c:711 free_metapage fs/jfs/jfs_metapage.c:279 [inline] metapage_release_folio+0x478/0x5b0 fs/jfs/jfs_metapage.c:636 folio_invalidate mm/truncate.c:140 [inline] truncate_cleanup_folio+0xcb/0x190 mm/truncate.c:160 truncate_inode_pages_range+0x2d1/0xe30 mm/truncate.c:404 jfs_reconfigure+0x5ac/0xa00 fs/jfs/super.c:406 reconfigure_super+0x227/0x8a0 fs/super.c:1080 do_remount fs/namespace.c:3391 [inline] path_mount+0xdc5/0x10e0 fs/namespace.c:4151 do_mount fs/namespace.c:4172 [inline] __do_sys_mount fs/namespace.c:4361 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4338 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803b8169c0 which belongs to the cache jfs_mp of size 248 The buggy address is located 40 bytes inside of freed 248-byte region [ffff88803b8169c0, ffff88803b816ab8) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3b816 flags: 0x80000000000000(node=0|zone=1) page_type: f5(slab) raw: 0080000000000000 ffff88801e339dc0 dead000000000122 0000000000000000 raw: 0000000000000000 00000008000d000d 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 0xd2800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5797, tgid 5797 (syz-executor), ts 94060221660, free_ts 94059872304 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250 alloc_slab_page mm/slub.c:3292 [inline] allocate_slab+0x77/0x660 mm/slub.c:3481 new_slab mm/slub.c:3539 [inline] refill_objects+0x334/0x3c0 mm/slub.c:7175 refill_sheaf mm/slub.c:2812 [inline] __pcs_replace_empty_main+0x35c/0x710 mm/slub.c:4615 alloc_from_pcs mm/slub.c:4717 [inline] slab_alloc_node mm/slub.c:4851 [inline] kmem_cache_alloc_noprof+0x433/0x680 mm/slub.c:4873 mempool_alloc_noprof+0x1d4/0x300 mm/mempool.c:566 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline] __get_metapage+0x50c/0xde0 fs/jfs/jfs_metapage.c:760 diSync+0xc4/0x8d0 fs/jfs/jfs_imap.c:216 diUnmount+0xc8/0x130 fs/jfs/jfs_imap.c:185 jfs_umount+0x1d7/0x3c0 fs/jfs/jfs_umount.c:72 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646 kill_block_super+0x44/0x90 fs/super.c:1725 deactivate_locked_super+0xbc/0x130 fs/super.c:476 page last free pid 5797 tgid 5797 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] free_unref_folios+0xe7b/0x1c70 mm/page_alloc.c:3040 folios_put_refs+0x56f/0x680 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] truncate_inode_pages_range+0x3e0/0xe30 mm/truncate.c:408 diUnmount+0xf7/0x130 fs/jfs/jfs_imap.c:190 jfs_umount+0x191/0x3c0 fs/jfs/jfs_umount.c:63 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646 kill_block_super+0x44/0x90 fs/super.c:1725 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88803b816880: fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803b816900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803b816980: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ^ ffff88803b816a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803b816a80: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc 00 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