================================================================== BUG: KASAN: slab-use-after-free in jfs_readdir+0x118f/0x3ae0 fs/jfs/jfs_dtree.c:2881 Read of size 8 at addr ffff88805e750168 by task syz.4.68/6278 CPU: 0 UID: 0 PID: 6278 Comm: syz.4.68 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 jfs_readdir+0x118f/0x3ae0 fs/jfs/jfs_dtree.c:2881 wrap_directory_iterator+0x99/0xe0 fs/readdir.c:65 iterate_dir+0x3a5/0x580 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/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3d5617f749 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:00007f3d543bd038 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 00007f3d563d6090 RCX: 00007f3d5617f749 RDX: 0000000000000022 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007f3d56203f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3d563d6128 R14: 00007f3d563d6090 R15: 00007fffdf25cea8 Allocated by task 6276: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4978 [inline] slab_alloc_node mm/slub.c:5288 [inline] kmem_cache_alloc_noprof+0x181/0x6b0 mm/slub.c:5295 mempool_alloc_noprof+0x1a0/0x4e0 mm/mempool.c:426 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline] __get_metapage+0x509/0xde0 fs/jfs/jfs_metapage.c:760 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_mknod+0x640/0x960 fs/jfs/namei.c:1410 vfs_mknod+0x37f/0x3c0 fs/namei.c:4322 do_mknodat+0x385/0x4d0 fs/namei.c:-1 __do_sys_mknod fs/namei.c:4405 [inline] __se_sys_mknod fs/namei.c:4403 [inline] __x64_sys_mknod+0x8c/0xa0 fs/namei.c:4403 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6278: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2543 [inline] slab_free mm/slub.c:6642 [inline] kmem_cache_free+0x19a/0x910 mm/slub.c:6752 free_metapage fs/jfs/jfs_metapage.c:279 [inline] drop_metapage fs/jfs/jfs_metapage.c:316 [inline] release_metapage+0x84c/0xab0 fs/jfs/jfs_metapage.c:892 dtReadNext fs/jfs/jfs_dtree.c:3202 [inline] jfs_readdir+0xece/0x3ae0 fs/jfs/jfs_dtree.c:2874 wrap_directory_iterator+0x99/0xe0 fs/readdir.c:65 iterate_dir+0x3a5/0x580 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/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88805e750138 which belongs to the cache jfs_mp of size 248 The buggy address is located 48 bytes inside of freed 248-byte region [ffff88805e750138, ffff88805e750230) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5e750 flags: 0x80000000000000(node=0|zone=1) page_type: f5(slab) raw: 0080000000000000 ffff88801d3e4b40 dead000000000122 0000000000000000 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 6276, tgid 6275 (syz.4.68), ts 142106646176, free_ts 141916880225 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1845 prep_new_page mm/page_alloc.c:1853 [inline] get_page_from_freelist+0x28c0/0x2960 mm/page_alloc.c:3879 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5178 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3059 [inline] allocate_slab+0x96/0x350 mm/slub.c:3232 new_slab mm/slub.c:3286 [inline] ___slab_alloc+0xb10/0x1400 mm/slub.c:4655 __slab_alloc+0xc6/0x1f0 mm/slub.c:4778 __slab_alloc_node mm/slub.c:4854 [inline] slab_alloc_node mm/slub.c:5276 [inline] kmem_cache_alloc_noprof+0xec/0x6b0 mm/slub.c:5295 mempool_alloc_noprof+0x1a0/0x4e0 mm/mempool.c:426 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline] __get_metapage+0x509/0xde0 fs/jfs/jfs_metapage.c:760 dbAllocCtl+0xd6/0x9c0 fs/jfs/jfs_dmap.c:1813 dbAllocAG+0x1e6/0xff0 fs/jfs/jfs_dmap.c:1353 dbAlloc+0x5a8/0xba0 fs/jfs/jfs_dmap.c:877 dtSplitUp fs/jfs/jfs_dtree.c:982 [inline] dtInsert+0xad5/0x5f40 fs/jfs/jfs_dtree.c:871 jfs_mknod+0x640/0x960 fs/jfs/namei.c:1410 vfs_mknod+0x37f/0x3c0 fs/namei.c:4322 page last free pid 28 tgid 28 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xfb6/0x1140 mm/page_alloc.c:2901 __tlb_remove_table_free mm/mmu_gather.c:227 [inline] tlb_remove_table_rcu+0x85/0x100 mm/mmu_gather.c:290 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core kernel/rcu/tree.c:2861 [inline] rcu_cpu_kthread+0xbf6/0x1b50 kernel/rcu/tree.c:2949 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff88805e750000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88805e750080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc >ffff88805e750100: fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb ^ ffff88805e750180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805e750200: fb fb fb fb fb fb fc fc fc fc fc fc fc fc 00 00 ==================================================================