================================================================== BUG: KASAN: use-after-free in drop_metapage fs/jfs/jfs_metapage.c:222 [inline] BUG: KASAN: use-after-free in release_metapage+0x819/0xe10 fs/jfs/jfs_metapage.c:758 Read of size 8 at addr ffff888073845cc0 by task jfsCommit/276 CPU: 0 PID: 276 Comm: jfsCommit Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 drop_metapage fs/jfs/jfs_metapage.c:222 [inline] release_metapage+0x819/0xe10 fs/jfs/jfs_metapage.c:758 txUnlock+0x427/0xcb0 fs/jfs/jfs_txnmgr.c:948 txLazyCommit fs/jfs/jfs_txnmgr.c:2717 [inline] jfs_lazycommit+0x583/0xb20 fs/jfs/jfs_txnmgr.c:2767 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Allocated by task 4317: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x100/0x290 mm/slub.c:3238 mempool_alloc+0x18f/0x4e0 mm/mempool.c:393 alloc_metapage fs/jfs/jfs_metapage.c:175 [inline] __get_metapage+0x5e8/0x1060 fs/jfs/jfs_metapage.c:652 dtSplitRoot+0x1e5/0x1510 fs/jfs/jfs_dtree.c:1910 dtSplitUp fs/jfs/jfs_dtree.c:993 [inline] dtInsert+0xe20/0x57a0 fs/jfs/jfs_dtree.c:871 jfs_rename+0x7b9/0x16a0 fs/jfs/namei.c:1224 vfs_rename+0xbbf/0x10d0 fs/namei.c:4840 do_renameat2+0xa83/0xf70 fs/namei.c:4993 __do_sys_rename fs/namei.c:5039 [inline] __se_sys_rename fs/namei.c:5037 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:5037 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 4317: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kmem_cache_free+0x8f/0x210 mm/slub.c:3520 free_metapage fs/jfs/jfs_metapage.c:190 [inline] drop_metapage fs/jfs/jfs_metapage.c:227 [inline] release_metapage+0x97b/0xe10 fs/jfs/jfs_metapage.c:758 dtSearch+0x1c25/0x2050 fs/jfs/jfs_dtree.c:624 jfs_lookup+0x152/0x380 fs/jfs/namei.c:1459 lookup_one_qstr_excl+0x10e/0x240 fs/namei.c:1571 filename_create+0x21e/0x450 fs/namei.c:3844 do_mkdirat+0x9d/0x5a0 fs/namei.c:4088 __do_sys_mkdirat fs/namei.c:4113 [inline] __se_sys_mkdirat fs/namei.c:4111 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4111 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff888073845c98 which belongs to the cache jfs_mp of size 184 The buggy address is located 40 bytes inside of 184-byte region [ffff888073845c98, ffff888073845d50) The buggy address belongs to the page: page:ffffea0001ce1140 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x73845 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 0000000000000000 dead000000000122 ffff88801dab9140 raw: 0000000000000000 0000000000100010 00000001ffffffff 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 0x192800(GFP_NOWAIT|__GFP_NOWARN|__GFP_NORETRY|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4317, ts 78003360666, free_ts 78002404883 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x195/0x290 mm/slub.c:3238 mempool_alloc+0x18f/0x4e0 mm/mempool.c:393 alloc_metapage fs/jfs/jfs_metapage.c:175 [inline] __get_metapage+0x5e8/0x1060 fs/jfs/jfs_metapage.c:652 diReadSpecial+0x257/0x700 fs/jfs/jfs_imap.c:447 jfs_mount+0x6f/0x860 fs/jfs/jfs_mount.c:87 jfs_fill_super+0x50b/0xaf0 fs/jfs/super.c:561 mount_bdev+0x287/0x3c0 fs/super.c:1400 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3034 do_mount fs/namespace.c:3377 [inline] __do_sys_mount fs/namespace.c:3585 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3562 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x94/0x280 mm/page_alloc.c:3396 free_slab mm/slub.c:2020 [inline] discard_slab mm/slub.c:2026 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2512 put_cpu_partial+0x12d/0x190 mm/slub.c:2592 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x100/0x290 mm/slub.c:3238 anon_vma_chain_alloc mm/rmap.c:138 [inline] __anon_vma_prepare+0x66/0x410 mm/rmap.c:192 anon_vma_prepare include/linux/rmap.h:152 [inline] do_anonymous_page mm/memory.c:3836 [inline] handle_pte_fault mm/memory.c:4648 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x3b83/0x43b0 mm/memory.c:4883 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1357 handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1501 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 copy_user_enhanced_fast_string+0xe/0x40 arch/x86/lib/copy_user_64.S:205 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline] copyout lib/iov_iter.c:157 [inline] copy_page_to_iter_iovec lib/iov_iter.c:228 [inline] __copy_page_to_iter lib/iov_iter.c:861 [inline] copy_page_to_iter+0x49e/0x910 lib/iov_iter.c:889 Memory state around the buggy address: ffff888073845b80: fc fc fc fc 00 00 00 00 00 00 00 00 00 00 00 00 ffff888073845c00: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc >ffff888073845c80: fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888073845d00: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc ffff888073845d80: fc fc 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================