================================================================== BUG: KASAN: slab-use-after-free in jfs_readdir+0x10a8/0x33f0 fs/jfs/jfs_dtree.c:2878 Read of s[ 133.232145][ T7384] Read of size 8 at addr ffff8880600ebed0 by task syz.7.186/7384 CPU: 0 UID: 0 PID: 7384 Comm: syz.7.186 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 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 jfs_readdir+0x10a8/0x33f0 fs/jfs/jfs_dtree.c:2878 wrap_directory_iterator+0x99/0xe0 fs/readdir.c:67 iterate_dir+0x2f1/0x4e0 fs/readdir.c:110 __do_sys_getdents64 fs/readdir.c:399 [inline] __se_sys_getdents64+0xf1/0x280 fs/readdir.c:384 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 RIP: 0033:0x7fe92f97ce59 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:00007fe92dbd6028 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 00007fe92fbf5fa0 RCX: 00007fe92f97ce59 RDX: 0000000000000063 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007fe92fa12e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe92fbf6038 R14: 00007fe92fbf5fa0 R15: 00007ffffc008e88 Allocated by task 7384: 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+0x337/0x680 mm/slub.c:4946 mempool_alloc_noprof+0x1c5/0x300 mm/mempool.c:559 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline] __get_metapage+0x4ed/0xdf0 fs/jfs/jfs_metapage.c:761 dtReadFirst+0xbb/0x780 fs/jfs/jfs_dtree.c:3076 dtReadNext fs/jfs/jfs_dtree.c:3157 [inline] jfs_readdir+0x8bb/0x33f0 fs/jfs/jfs_dtree.c:2871 wrap_directory_iterator+0x99/0xe0 fs/readdir.c:67 iterate_dir+0x2f1/0x4e0 fs/readdir.c:110 __do_sys_getdents64 fs/readdir.c:399 [inline] __se_sys_getdents64+0xf1/0x280 fs/readdir.c:384 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 7384: 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+0x187/0x6c0 mm/slub.c:6437 mempool_free+0xf5/0x140 mm/mempool.c:704 free_metapage fs/jfs/jfs_metapage.c:280 [inline] drop_metapage fs/jfs/jfs_metapage.c:317 [inline] release_metapage+0x7eb/0xa50 fs/jfs/jfs_metapage.c:893 dtReadNext fs/jfs/jfs_dtree.c:3199 [inline] jfs_readdir+0xe35/0x33f0 fs/jfs/jfs_dtree.c:2871 wrap_directory_iterator+0x99/0xe0 fs/readdir.c:67 iterate_dir+0x2f1/0x4e0 fs/readdir.c:110 __do_sys_getdents64 fs/readdir.c:399 [inline] __se_sys_getdents64+0xf1/0x280 fs/readdir.c:384 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 ffff8880600ebea0 which belongs to the cache jfs_mp of size 248 The buggy address is located 48 bytes inside of freed 248-byte region [ffff8880600ebea0, ffff8880600ebf98) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x600eb flags: 0x80000000000000(node=0|zone=1) page_type: f5(slab) raw: 0080000000000000 ffff88801cf6c140 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 6054, tgid 6054 (syz-executor), ts 132537659094, free_ts 132537280855 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1853 prep_new_page mm/page_alloc.c:1861 [inline] get_page_from_freelist+0x2877/0x28f0 mm/page_alloc.c:3941 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5221 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+0x32b/0x3c0 mm/slub.c:7241 refill_sheaf mm/slub.c:2827 [inline] __pcs_replace_empty_main+0x335/0x6a0 mm/slub.c:4692 alloc_from_pcs mm/slub.c:4790 [inline] slab_alloc_node mm/slub.c:4924 [inline] kmem_cache_alloc_noprof+0x42f/0x680 mm/slub.c:4946 mempool_alloc_noprof+0x1c5/0x300 mm/mempool.c:559 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline] __get_metapage+0x4ed/0xdf0 fs/jfs/jfs_metapage.c:761 diWriteSpecial+0x1b4/0x460 fs/jfs/jfs_imap.c:518 diSync+0x69d/0x8d0 fs/jfs/jfs_imap.c:251 diUnmount+0xc8/0x130 fs/jfs/jfs_imap.c:185 jfs_umount+0x1b8/0x3b0 fs/jfs/jfs_umount.c:79 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 page last free pid 6054 tgid 6054 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1397 [inline] free_unref_folios+0xd11/0x1940 mm/page_alloc.c:2999 folios_put_refs+0x7f0/0x900 mm/swap.c:1008 folio_batch_release include/linux/folio_batch.h:101 [inline] truncate_inode_pages_range+0x3cd/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 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x73a/0x2360 kernel/exit.c:1004 do_group_exit+0x22d/0x2f0 kernel/exit.c:1147 __do_sys_exit_group kernel/exit.c:1158 [inline] __se_sys_exit_group kernel/exit.c:1156 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1156 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 Memory state around the buggy address: ffff8880600ebd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880600ebe00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880600ebe80: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880600ebf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880600ebf80: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================