================================================================== BUG: KASAN: slab-use-after-free in ocfs2_fault+0xd3/0x400 fs/ocfs2/mmap.c:41 Read [ 254.881512][ T7674] Read of size 8 at addr ffff888035a18b98 by task syz.5.248/7674 CPU: 1 UID: 0 PID: 7674 Comm: syz.5.248 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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 ocfs2_fault+0xd3/0x400 fs/ocfs2/mmap.c:41 __do_fault+0x138/0x390 mm/memory.c:5280 do_read_fault mm/memory.c:5698 [inline] do_fault mm/memory.c:5832 [inline] do_pte_missing mm/memory.c:4361 [inline] handle_pte_fault mm/memory.c:6177 [inline] __handle_mm_fault mm/memory.c:6318 [inline] handle_mm_fault+0x23c6/0x3400 mm/memory.c:6487 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x1685/0x2860 mm/gup.c:1428 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1860 __mm_populate+0x24c/0x380 mm/gup.c:1963 mm_populate include/linux/mm.h:3471 [inline] vm_mmap_pgoff+0x38a/0x4d0 mm/util.c:586 ksys_mmap_pgoff+0x4e9/0x720 mm/mmap.c:604 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: 0033:0x7fe8ecd1efc9 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:00007fe8eaf7e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fe8ecf75fa0 RCX: 00007fe8ecd1efc9 RDX: 00000000027ffff7 RSI: 0000000000600000 RDI: 0000200000000000 RBP: 00007fe8ecda1f91 R08: 0000000000000004 R09: 0000000000000000 R10: 0000000004012011 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe8ecf76038 R14: 00007fe8ecf75fa0 R15: 00007ffe1c03e0e8 Allocated by task 7674: 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:4970 [inline] slab_alloc_node mm/slub.c:5280 [inline] kmem_cache_alloc_noprof+0x181/0x6b0 mm/slub.c:5287 vm_area_alloc+0x24/0x140 mm/vma_init.c:32 __mmap_new_vma mm/vma.c:2461 [inline] __mmap_region mm/vma.c:2670 [inline] mmap_region+0xdd8/0x20f0 mm/vma.c:2740 do_mmap+0xc23/0x10c0 mm/mmap.c:558 vm_mmap_pgoff+0x2a9/0x4d0 mm/util.c:581 ksys_mmap_pgoff+0x4e9/0x720 mm/mmap.c:604 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 20: 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:2539 [inline] slab_free_after_rcu_debug+0x130/0x4e0 mm/slub.c:6688 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 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:559 slab_free_hook mm/slub.c:2500 [inline] slab_free mm/slub.c:6630 [inline] kmem_cache_free+0x71f/0x910 mm/slub.c:6740 remove_vma mm/vma.c:468 [inline] vms_complete_munmap_vmas+0x626/0x8a0 mm/vma.c:1293 do_vmi_align_munmap+0x372/0x450 mm/vma.c:1536 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1584 do_munmap+0xcf/0x120 mm/mmap.c:1068 mremap_to+0x2c8/0x790 mm/mremap.c:1374 do_mremap mm/mremap.c:1937 [inline] __do_sys_mremap mm/mremap.c:1993 [inline] __se_sys_mremap+0xd45/0xfb0 mm/mremap.c:1961 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 ffff888035a18b40 which belongs to the cache vm_area_struct of size 256 The buggy address is located 88 bytes inside of freed 256-byte region [ffff888035a18b40, ffff888035a18c40) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x35a18 memcg:ffff88803dbbd901 anon flags: 0x80000000000000(node=0|zone=1) page_type: f5(slab) raw: 0080000000000000 ffff888019ef9b40 ffffea0000ab4e00 dead000000000005 raw: 0000000000000000 00000000000c000c 00000000f5000000 ffff88803dbbd901 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5963, tgid 5963 (udevd), ts 112583455931, free_ts 112524829852 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x28c0/0x2960 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3055 [inline] allocate_slab+0x96/0x350 mm/slub.c:3228 new_slab mm/slub.c:3282 [inline] ___slab_alloc+0xb12/0x13f0 mm/slub.c:4651 __kmem_cache_alloc_bulk+0x1c0/0x5a0 mm/slub.c:7394 refill_sheaf mm/slub.c:2633 [inline] __pcs_replace_empty_main+0x301/0x530 mm/slub.c:5040 alloc_from_pcs mm/slub.c:5138 [inline] slab_alloc_node mm/slub.c:5265 [inline] kmem_cache_alloc_noprof+0x45e/0x6b0 mm/slub.c:5287 vm_area_dup+0x2b/0x670 mm/vma_init.c:123 __split_vma+0x1ad/0x9e0 mm/vma.c:515 vms_gather_munmap_vmas+0x2e2/0x12e0 mm/vma.c:1359 do_vmi_align_munmap+0x276/0x450 mm/vma.c:1527 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1584 __vm_munmap+0x207/0x380 mm/vma.c:3156 __do_sys_munmap mm/mmap.c:1080 [inline] __se_sys_munmap mm/mmap.c:1077 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:1077 page last free pid 5957 tgid 5957 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] free_unref_folios+0xc22/0x1860 mm/page_alloc.c:2963 folios_put_refs+0x569/0x670 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] truncate_inode_pages_range+0x349/0xda0 mm/truncate.c:383 kill_bdev block/bdev.c:91 [inline] blkdev_flush_mapping+0x10b/0x280 block/bdev.c:712 blkdev_put_whole block/bdev.c:719 [inline] bdev_release+0x422/0x660 block/bdev.c:1144 blkdev_release+0x15/0x20 block/fops.c:709 __fput+0x45b/0xa80 fs/file_table.c:468 fput_close_sync+0x119/0x200 fs/file_table.c:573 __do_sys_close fs/open.c:1589 [inline] __se_sys_close fs/open.c:1574 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1574 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 Memory state around the buggy address: ffff888035a18a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888035a18b00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff888035a18b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888035a18c00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888035a18c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================