================================================================== 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 ffff8880363d0ec8 by task syz.9.904/15456 CPU: 0 UID: 0 PID: 15456 Comm: syz.9.904 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 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 write_metapage fs/jfs/jfs_metapage.h:75 [inline] flush_metapage fs/jfs/jfs_metapage.h:81 [inline] ea_put fs/jfs/xattr.c:623 [inline] __jfs_setxattr+0xe37/0x1160 fs/jfs/xattr.c:792 jfs_initxattrs+0x18c/0x260 fs/jfs/xattr.c:1040 security_inode_init_security+0x296/0x3d0 security/security.c:1344 jfs_init_security+0x91/0xe0 fs/jfs/xattr.c:1052 jfs_mkdir+0x2c7/0xb00 fs/jfs/namei.c:240 vfs_mkdir+0x75d/0x870 fs/namei.c:5139 do_mkdirat+0x281/0x4c0 fs/namei.c:5173 __do_sys_mkdirat fs/namei.c:5195 [inline] __se_sys_mkdirat fs/namei.c:5193 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:5193 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5752439d97 Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 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:00007f574fe0de58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f574fe0dee0 RCX: 00007f5752439d97 RDX: 00000000000001ff RSI: 00002000000001c0 RDI: 00000000ffffff9c RBP: 0000200000000040 R08: 0000200000000240 R09: 0000000000000000 R10: 0000200000000040 R11: 0000000000000246 R12: 00002000000001c0 R13: 00007f574fe0dea0 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 15456: 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:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x188/0x6a0 mm/slub.c:5270 mempool_alloc_noprof+0x1d4/0x300 mm/mempool.c:567 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline] __get_metapage+0x50c/0xde0 fs/jfs/jfs_metapage.c:760 ea_get+0xb9a/0x1330 fs/jfs/xattr.c:528 __jfs_setxattr+0x5ba/0x1160 fs/jfs/xattr.c:727 jfs_initxattrs+0x18c/0x260 fs/jfs/xattr.c:1040 security_inode_init_security+0x296/0x3d0 security/security.c:1344 jfs_init_security+0x91/0xe0 fs/jfs/xattr.c:1052 jfs_mkdir+0x2c7/0xb00 fs/jfs/namei.c:240 vfs_mkdir+0x75d/0x870 fs/namei.c:5139 do_mkdirat+0x281/0x4c0 fs/namei.c:5173 __do_sys_mkdirat fs/namei.c:5195 [inline] __se_sys_mkdirat fs/namei.c:5193 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:5193 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 15453: 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:2540 [inline] slab_free mm/slub.c:6674 [inline] kmem_cache_free+0x18d/0x8c0 mm/slub.c:6789 mempool_free+0xf5/0x140 mm/mempool.c:712 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:1077 vfs_cmd_reconfigure fs/fsopen.c:268 [inline] vfs_fsconfig_locked+0x171/0x320 fs/fsopen.c:297 __do_sys_fsconfig fs/fsopen.c:473 [inline] __se_sys_fsconfig+0x7a1/0x8f0 fs/fsopen.c:350 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880363d0ea0 which belongs to the cache jfs_mp of size 248 The buggy address is located 40 bytes inside of freed 248-byte region [ffff8880363d0ea0, ffff8880363d0f98) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x363d0 flags: 0x80000000000000(node=0|zone=1) page_type: f5(slab) raw: 0080000000000000 ffff88801b3a1b40 ffffea0000c03240 0000000000000002 raw: 0000000000000000 00000000800d000d 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 5800, tgid 5800 (syz-executor), ts 123791783614, free_ts 123791604324 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x228/0x280 mm/page_alloc.c:1884 prep_new_page mm/page_alloc.c:1892 [inline] get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3945 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5240 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3a0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xaf8/0x13d0 mm/slub.c:4656 __slab_alloc+0xc5/0x1f0 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] kmem_cache_alloc_noprof+0x100/0x6a0 mm/slub.c:5270 mempool_alloc_noprof+0x1d4/0x300 mm/mempool.c:567 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline] __get_metapage+0x50c/0xde0 fs/jfs/jfs_metapage.c:760 dbSync+0xc7/0x8d0 fs/jfs/jfs_dmap.c:287 dbUnmount+0xd4/0x180 fs/jfs/jfs_dmap.c:259 jfs_umount+0x258/0x3c0 fs/jfs/jfs_umount.c:87 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x135/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1722 page last free pid 5800 tgid 5800 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1433 [inline] free_unref_folios+0xd5e/0x19d0 mm/page_alloc.c:3030 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+0x220/0x3c0 fs/jfs/jfs_umount.c:80 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x135/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1722 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1318 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:44 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:75 __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_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880363d0d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880363d0e00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc >ffff8880363d0e80: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880363d0f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880363d0f80: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================