================================================================== BUG: KASAN: slab-use-after-free in jfs_readdir+0x118c/0x3ac0 fs/jfs/jfs_dtree.c:2870 Read of size 8 at addr ffff88802b9669e0 by task syz.3.21/6088 CPU: 1 UID: 0 PID: 6088 Comm: syz.3.21 Not tainted 6.15.0-rc7-syzkaller-00099-g94305e83eccb #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:408 [inline] print_report+0xb4/0x290 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 jfs_readdir+0x118c/0x3ac0 fs/jfs/jfs_dtree.c:2870 wrap_directory_iterator+0x93/0xe0 fs/readdir.c:65 iterate_dir+0x5ac/0x770 fs/readdir.c:108 __do_sys_getdents64 fs/readdir.c:403 [inline] __se_sys_getdents64+0xe4/0x260 fs/readdir.c:389 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc16358e969 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:00007fc1643ca038 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 00007fc1637b6080 RCX: 00007fc16358e969 RDX: 0000000000000022 RSI: 0000000000000000 RDI: 000000000000000c RBP: 00007fc163610ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fc1637b6080 R15: 00007ffe97b8c4f8 Allocated by task 6077: 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:4147 [inline] slab_alloc_node mm/slub.c:4196 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4203 mempool_alloc_noprof+0x1a4/0x510 mm/mempool.c:402 alloc_metapage fs/jfs/jfs_metapage.c:182 [inline] __get_metapage+0x50f/0xdc0 fs/jfs/jfs_metapage.c:652 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+0xb9c/0xec0 fs/namei.c:5121 do_renameat2+0x878/0xc50 fs/namei.c:5270 __do_sys_rename fs/namei.c:5317 [inline] __se_sys_rename fs/namei.c:5315 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:5315 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6088: 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:2380 [inline] slab_free mm/slub.c:4642 [inline] kmem_cache_free+0x192/0x3f0 mm/slub.c:4744 free_metapage fs/jfs/jfs_metapage.c:197 [inline] drop_metapage fs/jfs/jfs_metapage.c:234 [inline] release_metapage+0x859/0xac0 fs/jfs/jfs_metapage.c:784 dtReadNext fs/jfs/jfs_dtree.c:3190 [inline] jfs_readdir+0xecb/0x3ac0 fs/jfs/jfs_dtree.c:2863 wrap_directory_iterator+0x93/0xe0 fs/readdir.c:65 iterate_dir+0x5ac/0x770 fs/readdir.c:108 __do_sys_getdents64 fs/readdir.c:403 [inline] __se_sys_getdents64+0xe4/0x260 fs/readdir.c:389 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88802b9669b0 which belongs to the cache jfs_mp of size 184 The buggy address is located 48 bytes inside of freed 184-byte region [ffff88802b9669b0, ffff88802b966a68) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2b966 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801d770a00 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080100010 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 6077, tgid 6076 (syz.3.21), ts 104256233675, free_ts 104232675905 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1714 prep_new_page mm/page_alloc.c:1722 [inline] get_page_from_freelist+0x21c7/0x22a0 mm/page_alloc.c:3684 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4966 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2450 [inline] allocate_slab+0x8a/0x3b0 mm/slub.c:2618 new_slab mm/slub.c:2672 [inline] ___slab_alloc+0xbfc/0x1480 mm/slub.c:3858 __slab_alloc mm/slub.c:3948 [inline] __slab_alloc_node mm/slub.c:4023 [inline] slab_alloc_node mm/slub.c:4184 [inline] kmem_cache_alloc_noprof+0x283/0x3c0 mm/slub.c:4203 mempool_alloc_noprof+0x1a4/0x510 mm/mempool.c:402 alloc_metapage fs/jfs/jfs_metapage.c:182 [inline] __get_metapage+0x50f/0xdc0 fs/jfs/jfs_metapage.c:652 diMount+0xc5/0xd80 fs/jfs/jfs_imap.c:111 jfs_mount+0xdc/0x870 fs/jfs/jfs_mount.c:100 jfs_fill_super+0x6bc/0xd90 fs/jfs/super.c:523 get_tree_bdev_flags+0x40b/0x4d0 fs/super.c:1636 vfs_get_tree+0x92/0x2b0 fs/super.c:1759 do_new_mount+0x24a/0xa40 fs/namespace.c:3881 do_mount fs/namespace.c:4221 [inline] __do_sys_mount fs/namespace.c:4432 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4409 page last free pid 6079 tgid 6078 stack trace: create_dummy_stack mm/page_owner.c:94 [inline] register_dummy_stack+0x89/0xe0 mm/page_owner.c:100 init_page_owner+0x29/0x7b0 mm/page_owner.c:118 invoke_init_callbacks mm/page_ext.c:148 [inline] page_ext_init+0x72e/0x790 mm/page_ext.c:497 mm_core_init+0x5b/0x70 mm/mm_init.c:2783 Memory state around the buggy address: ffff88802b966880: fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 00 ffff88802b966900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc >ffff88802b966980: fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb ^ ffff88802b966a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff88802b966a80: fc fc fc fc fc 00 00 00 00 00 00 00 00 00 00 00 ==================================================================