================================================================== BUG: KASAN: slab-use-after-free in ocfs2_fault+0xdb/0x440 fs/ocfs2/mmap.c:41 Read of size 8 at addr ffff888065873558 by task syz.2.2191/25670 CPU: 0 UID: 0 PID: 25670 Comm: syz.2.2191 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 ocfs2_fault+0xdb/0x440 fs/ocfs2/mmap.c:41 __do_fault+0x138/0x390 mm/memory.c:5363 do_read_fault mm/memory.c:5798 [inline] do_fault mm/memory.c:5932 [inline] do_pte_missing+0x17fd/0x2d30 mm/memory.c:4477 handle_pte_fault mm/memory.c:6316 [inline] __handle_mm_fault mm/memory.c:6454 [inline] handle_mm_fault+0xd0a/0x13c0 mm/memory.c:6623 do_user_addr_fault+0x75b/0x1340 arch/x86/mm/fault.c:1385 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 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 20 c2 b5 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:ffffc90004b276a8 EFLAGS: 00050202 RAX: ffffffff820e9301 RBX: 0000000000000c7b RCX: ffff88802be95ac0 RDX: 0000000000000002 RSI: 0000200000001000 RDI: 0000200000001c7b RBP: dffffc0000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000001 R12: 00007ffffffff000 R13: 0000200000001000 R14: 0000200000001000 R15: 0000200000001c7b fault_in_iov_iter_readable+0x1b4/0x2f0 lib/iov_iter.c:106 generic_perform_write+0x765/0x8b0 mm/filemap.c:4363 ocfs2_file_write_iter+0x1666/0x1ed0 fs/ocfs2/file.c:2476 do_iter_readv_writev+0x62b/0x8d0 fs/read_write.c:-1 vfs_writev+0x345/0x9a0 fs/read_write.c:1059 do_pwritev fs/read_write.c:1155 [inline] __do_sys_pwritev2 fs/read_write.c:1213 [inline] __se_sys_pwritev2+0x187/0x2b0 fs/read_write.c:1204 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2c2fe8c629 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2c2e0bd028 EFLAGS: 00000246 ORIG_RAX: 0000000000000148 RAX: ffffffffffffffda RBX: 00007f2c30106090 RCX: 00007f2c2fe8c629 RDX: 0000000000000001 RSI: 0000200000000100 RDI: 0000000000000006 RBP: 00007f2c2ff22b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000005405 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2c30106128 R14: 00007f2c30106090 R15: 00007ffc4f510c58 Allocated by task 25697: 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:4501 [inline] slab_alloc_node mm/slub.c:4830 [inline] kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4837 vm_area_alloc+0x24/0x140 mm/vma_init.c:32 __mmap_new_vma mm/vma.c:2517 [inline] __mmap_region mm/vma.c:2759 [inline] mmap_region+0x112c/0x2230 mm/vma.c:2837 do_mmap+0xc2f/0x10c0 mm/mmap.c:559 vm_mmap_pgoff+0x2cc/0x4f0 mm/util.c:581 ksys_mmap_pgoff+0x4e8/0x720 mm/mmap.c:605 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 28: 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:2687 [inline] slab_free_after_rcu_debug+0x126/0x220 mm/slub.c:6189 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core kernel/rcu/tree.c:2869 [inline] rcu_cpu_kthread+0x99e/0x1470 kernel/rcu/tree.c:2957 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 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:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 slab_free_hook mm/slub.c:2648 [inline] slab_free mm/slub.c:6124 [inline] kmem_cache_free+0x4fb/0x6b0 mm/slub.c:6254 remove_vma mm/vma.c:470 [inline] vms_complete_munmap_vmas+0x929/0xc60 mm/vma.c:1342 do_vmi_align_munmap+0x3bd/0x4d0 mm/vma.c:1585 do_vmi_munmap+0x252/0x2d0 mm/vma.c:1633 __vm_munmap+0x22c/0x3d0 mm/vma.c:3254 __do_sys_munmap mm/mmap.c:1078 [inline] __se_sys_munmap mm/mmap.c:1075 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:1075 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888065873500 which belongs to the cache vm_area_struct of size 256 The buggy address is located 88 bytes inside of freed 256-byte region [ffff888065873500, ffff888065873600) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x65873 memcg:ffff888065873f01 flags: 0x80000000000000(node=0|zone=1) page_type: f5(slab) raw: 0080000000000000 ffff888140410500 dead000000000100 dead000000000122 raw: 0000000000000000 00000008000c000c 00000000f5000000 ffff888065873f01 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 25328, tgid 25328 (rm), ts 1202555085029, free_ts 1202552072639 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250 alloc_slab_page mm/slub.c:3255 [inline] allocate_slab+0x77/0x660 mm/slub.c:3444 new_slab mm/slub.c:3502 [inline] refill_objects+0x334/0x3c0 mm/slub.c:7134 refill_sheaf mm/slub.c:2804 [inline] __pcs_replace_empty_main+0x328/0x5f0 mm/slub.c:4578 alloc_from_pcs mm/slub.c:4681 [inline] slab_alloc_node mm/slub.c:4815 [inline] kmem_cache_alloc_noprof+0x433/0x680 mm/slub.c:4837 vm_area_dup+0x2b/0x670 mm/vma_init.c:123 __split_vma+0x1e4/0xa30 mm/vma.c:513 vms_gather_munmap_vmas+0x32d/0x1370 mm/vma.c:1408 __mmap_setup mm/vma.c:2411 [inline] __mmap_region mm/vma.c:2741 [inline] mmap_region+0x87f/0x2230 mm/vma.c:2837 do_mmap+0xc2f/0x10c0 mm/mmap.c:559 vm_mmap_pgoff+0x2cc/0x4f0 mm/util.c:581 ksys_mmap_pgoff+0x4e8/0x720 mm/mmap.c:605 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 25328 tgid 25328 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xfe3/0x1170 mm/page_alloc.c:2978 __slab_free+0x24f/0x2a0 mm/slub.c:5532 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4501 [inline] slab_alloc_node mm/slub.c:4830 [inline] __do_kmalloc_node mm/slub.c:5218 [inline] __kmalloc_noprof+0x399/0x7b0 mm/slub.c:5231 kmalloc_noprof include/linux/slab.h:966 [inline] tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x283/0x560 security/tomoyo/file.c:827 security_inode_getattr+0x12b/0x310 security/security.c:1869 vfs_getattr fs/stat.c:259 [inline] vfs_fstat fs/stat.c:281 [inline] __do_sys_newfstat fs/stat.c:551 [inline] __se_sys_newfstat fs/stat.c:546 [inline] __x64_sys_newfstat+0x13b/0x270 fs/stat.c:546 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888065873400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888065873480: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc >ffff888065873500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888065873580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888065873600: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ================================================================== ---------------- 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 20 c2 b5 ff call 0xffb5c23c 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