================================================================== BUG: KASAN: slab-use-after-free in jfs_readdir+0x118c/0x3ae0 fs/jfs/jfs_dtree.c:2881 Read of size 8 at addr ffff888050cdd220 by task syz.5.79/6777 CPU: 1 UID: 0 PID: 6777 Comm: syz.5.79 Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #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:378 [inline] print_report+0xca/0x230 mm/kasan/report.c:480 kasan_report+0x118/0x150 mm/kasan/report.c:593 jfs_readdir+0x118c/0x3ae0 fs/jfs/jfs_dtree.c:2881 wrap_directory_iterator+0x96/0xe0 fs/readdir.c:65 iterate_dir+0x5af/0x770 fs/readdir.c:108 __do_sys_getdents64 fs/readdir.c:410 [inline] __se_sys_getdents64+0xe4/0x260 fs/readdir.c:396 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: 0033:0x7f8e99b8e929 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:00007f8e979d5038 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 00007f8e99db6160 RCX: 00007f8e99b8e929 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006 RBP: 00007f8e99c10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8e99db6160 R15: 00007ffe185489b8 Allocated by task 6760: 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_noprof+0x1c1/0x3c0 mm/slub.c:4204 mempool_alloc_noprof+0x1a7/0x510 mm/mempool.c:402 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline] __get_metapage+0x509/0xde0 fs/jfs/jfs_metapage.c:758 dtSplitRoot+0x202/0x16c0 fs/jfs/jfs_dtree.c:1910 dtSplitUp fs/jfs/jfs_dtree.c:993 [inline] dtInsert+0xef8/0x5f40 fs/jfs/jfs_dtree.c:871 jfs_rename+0x7bc/0x1610 fs/jfs/namei.c:1225 vfs_rename+0xb99/0xec0 fs/namei.c:5137 do_renameat2+0x878/0xc50 fs/namei.c:5286 __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 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6777: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kmem_cache_free+0x18f/0x400 mm/slub.c:4745 free_metapage fs/jfs/jfs_metapage.c:279 [inline] drop_metapage fs/jfs/jfs_metapage.c:316 [inline] release_metapage+0x859/0xac0 fs/jfs/jfs_metapage.c:890 dtReadNext fs/jfs/jfs_dtree.c:3202 [inline] jfs_readdir+0xecb/0x3ae0 fs/jfs/jfs_dtree.c:2874 wrap_directory_iterator+0x96/0xe0 fs/readdir.c:65 iterate_dir+0x5af/0x770 fs/readdir.c:108 __do_sys_getdents64 fs/readdir.c:410 [inline] __se_sys_getdents64+0xe4/0x260 fs/readdir.c:396 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 ffff888050cdd1f0 which belongs to the cache jfs_mp of size 184 The buggy address is located 48 bytes inside of freed 184-byte region [ffff888050cdd1f0, ffff888050cdd2a8) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x50cdd flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff8881466a33c0 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000100010 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 5845, tgid 5845 (syz-executor), ts 109477590315, free_ts 109477471646 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_noprof+0x283/0x3c0 mm/slub.c:4204 mempool_alloc_noprof+0x1a7/0x510 mm/mempool.c:402 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline] __get_metapage+0x509/0xde0 fs/jfs/jfs_metapage.c:758 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+0x132/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1755 deactivate_locked_super+0xbc/0x130 fs/super.c:474 page last free pid 5845 tgid 5845 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] free_unref_folios+0xcd2/0x1570 mm/page_alloc.c:2763 folios_put_refs+0x559/0x640 mm/swap.c:992 folio_batch_release include/linux/pagevec.h:101 [inline] truncate_inode_pages_range+0x346/0xda0 mm/truncate.c:383 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+0x132/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1755 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888050cdd100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888050cdd180: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fa fb >ffff888050cdd200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888050cdd280: fb fb fb fb fb fc fc fc fc fc fc fc fc 00 00 00 ffff888050cdd300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================