================================================================== BUG: KASAN: slab-use-after-free in drop_metapage fs/jfs/jfs_metapage.c:312 [inline] BUG: KASAN: slab-use-after-free in release_metapage+0x717/0xa60 fs/jfs/jfs_metapage.c:893 Read of size 8 at addr ffff88808c9c3500 by task jfsCommit/115 CPU: 1 UID: 0 PID: 115 Comm: jfsCommit Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 drop_metapage fs/jfs/jfs_metapage.c:312 [inline] release_metapage+0x717/0xa60 fs/jfs/jfs_metapage.c:893 txUnlock+0x51c/0xde0 fs/jfs/jfs_txnmgr.c:949 txLazyCommit fs/jfs/jfs_txnmgr.c:2684 [inline] jfs_lazycommit+0x59f/0xac0 fs/jfs/jfs_txnmgr.c:2735 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 25313: 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:4610 [inline] slab_alloc_node mm/slub.c:4939 [inline] kmem_cache_alloc_noprof+0x2b8/0x650 mm/slub.c:4946 mempool_alloc_noprof+0x1bf/0x300 mm/mempool.c:559 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline] __get_metapage+0x4ed/0xdf0 fs/jfs/jfs_metapage.c:761 dtSplitRoot+0x216/0x1900 fs/jfs/jfs_dtree.c:1907 dtSplitUp fs/jfs/jfs_dtree.c:990 [inline] dtInsert+0xedd/0x5cb0 fs/jfs/jfs_dtree.c:868 jfs_symlink+0x8a1/0xfb0 fs/jfs/namei.c:1021 vfs_symlink+0x18b/0x330 fs/namei.c:5656 filename_symlinkat+0x1cd/0x410 fs/namei.c:5681 __do_sys_symlinkat fs/namei.c:5701 [inline] __se_sys_symlinkat+0x4e/0x2b0 fs/namei.c:5696 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 25322: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 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:2700 [inline] slab_free mm/slub.c:6310 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6437 mempool_free+0xec/0x130 mm/mempool.c:704 free_metapage fs/jfs/jfs_metapage.c:280 [inline] metapage_release_folio+0x462/0x590 fs/jfs/jfs_metapage.c:637 folio_invalidate mm/truncate.c:140 [inline] truncate_cleanup_folio+0xcb/0x190 mm/truncate.c:160 truncate_inode_pages_range+0x2c1/0xd80 mm/truncate.c:404 jfs_reconfigure+0x592/0x990 fs/jfs/super.c:406 reconfigure_super+0x232/0x8f0 fs/super.c:1020 do_remount fs/namespace.c:3407 [inline] path_mount+0xd4b/0x1040 fs/namespace.c:4153 do_mount fs/namespace.c:4174 [inline] __do_sys_mount fs/namespace.c:4390 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4367 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88808c9c34d8 which belongs to the cache jfs_mp of size 184 The buggy address is located 40 bytes inside of freed 184-byte region [ffff88808c9c34d8, ffff88808c9c3590) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x8c9c3 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801cb988c0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 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 11393, tgid 11393 (syz-executor), ts 1173559141531, free_ts 1173559061011 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0x21fa/0x2270 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3289 [inline] allocate_slab+0x74/0x5d0 mm/slub.c:3404 new_slab mm/slub.c:3447 [inline] refill_objects+0x328/0x3c0 mm/slub.c:7241 refill_sheaf mm/slub.c:2827 [inline] __pcs_replace_empty_main+0x2e0/0x6b0 mm/slub.c:4692 alloc_from_pcs mm/slub.c:4790 [inline] slab_alloc_node mm/slub.c:4924 [inline] kmem_cache_alloc_noprof+0x373/0x650 mm/slub.c:4946 mempool_alloc_noprof+0x1bf/0x300 mm/mempool.c:559 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline] __get_metapage+0x4ed/0xdf0 fs/jfs/jfs_metapage.c:761 diSync+0xc4/0x8d0 fs/jfs/jfs_imap.c:216 diUnmount+0xc8/0x130 fs/jfs/jfs_imap.c:185 jfs_umount+0x209/0x3b0 fs/jfs/jfs_umount.c:87 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x13d/0x2d0 fs/super.c:647 kill_block_super+0x44/0x90 fs/super.c:1665 deactivate_locked_super+0xbc/0x130 fs/super.c:477 page last free pid 11393 tgid 11393 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] free_unref_folios+0xd87/0x14a0 mm/page_alloc.c:3011 folios_put_refs+0x9e9/0xb30 mm/swap.c:1057 folio_batch_release include/linux/folio_batch.h:101 [inline] truncate_inode_pages_range+0x3ca/0xd80 mm/truncate.c:408 diUnmount+0xf7/0x130 fs/jfs/jfs_imap.c:190 jfs_umount+0x174/0x3b0 fs/jfs/jfs_umount.c:70 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x13d/0x2d0 fs/super.c:647 kill_block_super+0x44/0x90 fs/super.c:1665 deactivate_locked_super+0xbc/0x130 fs/super.c:477 cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317 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:70 [inline] exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88808c9c3400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808c9c3480: fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb fb >ffff88808c9c3500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88808c9c3580: fb fb fc fc fc fc fc fc fc fc fa fb fb fb fb fb ffff88808c9c3600: fb fb fb fb fb fb fb fb 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