================================================================== BUG: KASAN: slab-use-after-free in ocfs2_fault+0xd3/0x3e0 fs/ocfs2/mmap.c:41 Read of size 8 at addr ffff88803b3a77d8 by task syz.3.158/6887 CPU: 0 UID: 0 PID: 6887 Comm: syz.3.158 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+0xe8/0x150 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+0xd3/0x3e0 fs/ocfs2/mmap.c:41 __do_fault+0x138/0x390 mm/memory.c:5320 do_read_fault mm/memory.c:5755 [inline] do_fault mm/memory.c:5889 [inline] do_pte_missing+0x18ca/0x27a0 mm/memory.c:4401 handle_pte_fault mm/memory.c:6273 [inline] __handle_mm_fault mm/memory.c:6411 [inline] handle_mm_fault+0xcc1/0x1330 mm/memory.c:6580 do_user_addr_fault+0x764/0x1380 arch/x86/mm/fault.c:1387 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x71/0xd0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0010:fault_in_readable+0x8e/0x130 mm/gup.c:2161 Code: a9 00 00 00 0f 01 cb 0f ae e8 4d 85 f6 40 0f 95 c5 4c 89 ff 4c 89 f6 e8 70 a6 b8 ff 4d 39 f7 0f 97 c0 40 84 c5 74 43 4d 89 f5 <41> 8a 45 00 88 44 24 07 49 81 e5 00 f0 ff ff 4d 8d a5 00 10 00 00 RSP: 0018:ffffc9000867f668 EFLAGS: 00050202 RAX: ffffffff82070801 RBX: 0000000000001000 RCX: ffff88802d60dac0 RDX: 0000000000000002 RSI: 0000200000001000 RDI: 0000200000002000 RBP: dffffc0000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000001 R12: 00007ffffffff000 R13: 0000200000001000 R14: 0000200000001000 R15: 0000200000002000 fault_in_iov_iter_readable+0x1b4/0x2f0 lib/iov_iter.c:106 generic_perform_write+0x77b/0x8c0 mm/filemap.c:4363 __generic_file_write_iter+0x1b1/0x240 mm/filemap.c:4428 ocfs2_file_write_iter+0x1585/0x1d00 fs/ocfs2/file.c:2475 do_iter_readv_writev+0x635/0x8d0 fs/read_write.c:-1 vfs_writev+0x323/0x970 fs/read_write.c:1057 do_pwritev fs/read_write.c:1153 [inline] __do_sys_pwritev2 fs/read_write.c:1211 [inline] __se_sys_pwritev2+0x17c/0x2a0 fs/read_write.c:1202 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb88819f749 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:00007fb8863fe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000148 RAX: ffffffffffffffda RBX: 00007fb8883f5fa0 RCX: 00007fb88819f749 RDX: 0000000000000001 RSI: 0000200000000240 RDI: 0000000000000005 RBP: 00007fb888223f91 R08: 0000000000000000 R09: 0000000000000003 R10: 0000000000002000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb8883f6038 R14: 00007fb8883f5fa0 R15: 00007ffc713c5078 Allocated by task 6887: 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:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x18d/0x6c0 mm/slub.c:5270 vm_area_alloc+0x24/0x140 mm/vma_init.c:32 __mmap_new_vma mm/vma.c:2469 [inline] __mmap_region mm/vma.c:2708 [inline] mmap_region+0xe0b/0x1d00 mm/vma.c:2786 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+0xec/0xf80 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:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 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:2540 [inline] slab_free_after_rcu_debug+0x12d/0x490 mm/slub.c:6729 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core kernel/rcu/tree.c:2857 [inline] rcu_cpu_kthread+0xba5/0x1af0 kernel/rcu/tree.c:2945 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 slab_free_hook mm/slub.c:2501 [inline] slab_free mm/slub.c:6670 [inline] kmem_cache_free+0x711/0x8d0 mm/slub.c:6781 remove_vma mm/vma.c:462 [inline] vms_complete_munmap_vmas+0x626/0x8a0 mm/vma.c:1296 do_vmi_align_munmap+0x372/0x450 mm/vma.c:1539 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1587 __vm_munmap+0x207/0x380 mm/vma.c:3203 __do_sys_munmap mm/mmap.c:1077 [inline] __se_sys_munmap mm/mmap.c:1074 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:1074 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803b3a7780 which belongs to the cache vm_area_struct of size 256 The buggy address is located 88 bytes inside of freed 256-byte region [ffff88803b3a7780, ffff88803b3a7880) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3b3a7 memcg:ffff888034587d81 flags: 0x80000000000000(node=0|zone=1) page_type: f5(slab) raw: 0080000000000000 ffff888140408b40 dead000000000100 dead000000000122 raw: 0000000000000000 00000000000c000c 00000000f5000000 ffff888034587d81 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5456, tgid 5456 (run-parts), ts 47967865586, free_ts 47953687899 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1857 prep_new_page mm/page_alloc.c:1865 [inline] get_page_from_freelist+0x28c0/0x2960 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3b0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xb10/0x13e0 mm/slub.c:4656 __kmem_cache_alloc_bulk+0x1b8/0x560 mm/slub.c:7431 refill_sheaf mm/slub.c:2650 [inline] __pcs_replace_empty_main+0x307/0x560 mm/slub.c:5023 alloc_from_pcs mm/slub.c:5121 [inline] slab_alloc_node mm/slub.c:5248 [inline] kmem_cache_alloc_noprof+0x46a/0x6c0 mm/slub.c:5270 vm_area_alloc+0x24/0x140 mm/vma_init.c:32 __mmap_new_vma mm/vma.c:2469 [inline] __mmap_region mm/vma.c:2708 [inline] mmap_region+0xe0b/0x1d00 mm/vma.c:2786 do_mmap+0xc23/0x10c0 mm/mmap.c:558 vm_mmap_pgoff+0x2a9/0x4d0 mm/util.c:581 elf_map fs/binfmt_elf.c:395 [inline] elf_load+0x140/0x6c0 fs/binfmt_elf.c:422 load_elf_binary+0x1099/0x2750 fs/binfmt_elf.c:1188 search_binary_handler fs/exec.c:1669 [inline] exec_binprm fs/exec.c:1701 [inline] bprm_execve+0x92e/0x1400 fs/exec.c:1753 page last free pid 20 tgid 20 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0xfe1/0x1170 mm/page_alloc.c:2943 __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:2857 [inline] rcu_cpu_kthread+0xba5/0x1af0 kernel/rcu/tree.c:2945 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Memory state around the buggy address: ffff88803b3a7680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88803b3a7700: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc >ffff88803b3a7780: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803b3a7800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803b3a7880: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ================================================================== ---------------- Code disassembly (best guess): 0: a9 00 00 00 0f test $0xf000000,%eax 5: 01 cb add %ecx,%ebx 7: 0f ae e8 lfence a: 4d 85 f6 test %r14,%r14 d: 40 0f 95 c5 setne %bpl 11: 4c 89 ff mov %r15,%rdi 14: 4c 89 f6 mov %r14,%rsi 17: e8 70 a6 b8 ff call 0xffb8a68c 1c: 4d 39 f7 cmp %r14,%r15 1f: 0f 97 c0 seta %al 22: 40 84 c5 test %al,%bpl 25: 74 43 je 0x6a 27: 4d 89 f5 mov %r14,%r13 * 2a: 41 8a 45 00 mov 0x0(%r13),%al <-- trapping instruction 2e: 88 44 24 07 mov %al,0x7(%rsp) 32: 49 81 e5 00 f0 ff ff and $0xfffffffffffff000,%r13 39: 4d 8d a5 00 10 00 00 lea 0x1000(%r13),%r12