================================================================== BUG: KASAN: slab-use-after-free in ocfs2_fault+0xd3/0x3f0 fs/ocfs2/mmap.c:41 Read of size 8 at addr ffff88807e6e4558 by task syz.3.350/8871 CPU: 0 UID: 0 PID: 8871 Comm: syz.3.350 Not tainted 6.15.0-rc4-syzkaller-00256-g95d3481af6dc #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 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 ocfs2_fault+0xd3/0x3f0 fs/ocfs2/mmap.c:41 __do_fault+0x135/0x390 mm/memory.c:5098 do_shared_fault mm/memory.c:5582 [inline] do_fault mm/memory.c:5656 [inline] do_pte_missing mm/memory.c:4160 [inline] handle_pte_fault mm/memory.c:5997 [inline] __handle_mm_fault+0x17f9/0x5380 mm/memory.c:6140 handle_mm_fault+0x2d5/0x7f0 mm/memory.c:6309 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1388 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x68/0x110 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7ff4949566d8 Code: fc 89 37 c3 c5 fa 6f 06 c5 fa 6f 4c 16 f0 c5 fa 7f 07 c5 fa 7f 4c 17 f0 c3 66 0f 1f 84 00 00 00 00 00 48 8b 4c 16 f8 48 8b 36 <48> 89 37 48 89 4c 17 f8 c3 c5 fe 6f 54 16 e0 c5 fe 6f 5c 16 c0 c5 RSP: 002b:00007fff54f898b8 EFLAGS: 00010202 RAX: 0000200000002100 RBX: 0000000000000004 RCX: 007370756f726774 RDX: 000000000000000a RSI: 70756f7267746573 RDI: 0000200000002100 RBP: 00007ff494bb7ba0 R08: 00007ff494800000 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000009 R12: 00007ff494bb616c R13: 00007fff54f899b0 R14: fffffffffffffffe R15: 00007fff54f899d0 Allocated by task 8894: 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 vm_area_alloc+0x24/0x140 kernel/fork.c:441 __mmap_new_vma mm/vma.c:2402 [inline] __mmap_region mm/vma.c:2519 [inline] mmap_region+0xcf4/0x1e50 mm/vma.c:2597 do_mmap+0xc68/0x1100 mm/mmap.c:561 vm_mmap_pgoff+0x31b/0x4c0 mm/util.c:579 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:607 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 15: 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_after_rcu_debug+0x127/0x290 mm/slub.c:4692 rcu_do_batch kernel/rcu/tree.c:2568 [inline] rcu_core+0xca5/0x1710 kernel/rcu/tree.c:2824 handle_softirqs+0x283/0x870 kernel/softirq.c:579 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:164 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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:47 kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:548 slab_free_hook mm/slub.c:2341 [inline] slab_free mm/slub.c:4642 [inline] kmem_cache_free+0x2ee/0x3f0 mm/slub.c:4744 remove_vma mm/vma.c:430 [inline] vms_complete_munmap_vmas+0x626/0x8a0 mm/vma.c:1249 __mmap_complete mm/vma.c:2469 [inline] __mmap_region mm/vma.c:2535 [inline] mmap_region+0x1471/0x1e50 mm/vma.c:2597 do_mmap+0xc68/0x1100 mm/mmap.c:561 vm_mmap_pgoff+0x31b/0x4c0 mm/util.c:579 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:607 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 ffff88807e6e4500 which belongs to the cache vm_area_struct of size 256 The buggy address is located 88 bytes inside of freed 256-byte region [ffff88807e6e4500, ffff88807e6e4600) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7e6e4 memcg:ffff888024392281 anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b298b40 0000000000000000 dead000000000001 raw: 0000000000000000 00000000000c000c 00000000f5000000 ffff888024392281 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 8597, tgid 8597 (dhcpcd-run-hook), ts 270502061542, free_ts 267337564013 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1718 prep_new_page mm/page_alloc.c:1726 [inline] get_page_from_freelist+0x21c7/0x22a0 mm/page_alloc.c:3688 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4970 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 vm_area_dup+0x2b/0x5c0 kernel/fork.c:488 dup_mmap kernel/fork.c:672 [inline] dup_mm kernel/fork.c:1734 [inline] copy_mm+0xbe1/0x2100 kernel/fork.c:1786 copy_process+0x16d3/0x3b80 kernel/fork.c:2429 kernel_clone+0x224/0x7f0 kernel/fork.c:2844 __do_sys_clone kernel/fork.c:2987 [inline] __se_sys_clone kernel/fork.c:2971 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2971 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 page last free pid 8485 tgid 8484 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1262 [inline] __free_frozen_pages+0xb05/0xcd0 mm/page_alloc.c:2725 tlb_batch_list_free mm/mmu_gather.c:159 [inline] tlb_finish_mmu+0x112/0x1d0 mm/mmu_gather.c:499 exit_mmap+0x474/0xba0 mm/mmap.c:1297 __mmput+0x118/0x410 kernel/fork.c:1379 exit_mm+0x1da/0x2c0 kernel/exit.c:589 do_exit+0x859/0x2550 kernel/exit.c:940 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x125e/0x1310 kernel/signal.c:3034 arch_do_signal_or_restart+0x95/0x780 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x8b/0x120 kernel/entry/common.c:218 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88807e6e4400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88807e6e4480: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc >ffff88807e6e4500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807e6e4580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807e6e4600: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ==================================================================