================================================================== BUG: KASAN: slab-use-after-free in ocfs2_fault+0xd3/0x400 fs/ocfs2/mmap.c:41 Read of size 8 at addr ffff888030fd9418 by task syz.0.176/6976 CPU: 1 UID: 0 PID: 6976 Comm: syz.0.176 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 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+0x82/0x100 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 c0 f4 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:ffffc9000639f828 EFLAGS: 00050202 RAX: ffffffff8205ce01 RBX: 0000000000000001 RCX: ffff888025519e00 RDX: 0000000000000002 RSI: 0000200000000000 RDI: 0000200000000001 RBP: dffffc0000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000001 R12: 00007ffffffff000 R13: 0000200000000000 R14: 0000200000000000 R15: 0000200000000001 fault_in_iov_iter_readable+0x1b4/0x2f0 lib/iov_iter.c:94 generic_perform_write+0x77b/0x8c0 mm/filemap.c:4291 ocfs2_file_write_iter+0x157d/0x1d20 fs/ocfs2/file.c:2469 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5d5/0xb40 fs/read_write.c:686 ksys_pwrite64 fs/read_write.c:793 [inline] __do_sys_pwrite64 fs/read_write.c:801 [inline] __se_sys_pwrite64 fs/read_write.c:798 [inline] __x64_sys_pwrite64+0x196/0x220 fs/read_write.c:798 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: 0033:0x7fa801f2efc9 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:00007fa80018e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000012 RAX: ffffffffffffffda RBX: 00007fa802185fa0 RCX: 00007fa801f2efc9 RDX: 0000000000000001 RSI: 0000200000000000 RDI: 0000000000000006 RBP: 00007fa801fb1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000004fed0 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa802186038 R14: 00007fa802185fa0 R15: 00007ffecd2fa408 Allocated by task 6976: 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 28: 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 __mmap_complete mm/vma.c:2532 [inline] __mmap_region mm/vma.c:2678 [inline] mmap_region+0x11ef/0x20f0 mm/vma.c:2740 do_mmap+0xc23/0x10c0 mm/mmap.c:558 vm_mmap_pgoff+0x2a9/0x4d0 mm/util.c:581 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 ffff888030fd93c0 which belongs to the cache vm_area_struct of size 256 The buggy address is located 88 bytes inside of freed 256-byte region [ffff888030fd93c0, ffff888030fd94c0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x30fd9 memcg:ffff8880277de801 anon flags: 0x80000000000000(node=0|zone=1) page_type: f5(slab) raw: 0080000000000000 ffff888019ef9b40 0000000000000000 dead000000000001 raw: 0000000000000000 00000000000c000c 00000000f5000000 ffff8880277de801 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 5545, tgid 5545 (start-stop-daem), ts 57159909061, free_ts 49886522194 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 split_vma mm/vma.c:598 [inline] vma_modify+0x1328/0x1880 mm/vma.c:1631 vma_modify_flags+0x1e8/0x230 mm/vma.c:1649 mprotect_fixup+0x407/0x9c0 mm/mprotect.c:816 do_mprotect_pkey+0x8c5/0xcd0 mm/mprotect.c:990 __do_sys_mprotect mm/mprotect.c:1011 [inline] __se_sys_mprotect mm/mprotect.c:1008 [inline] __x64_sys_mprotect+0x80/0x90 mm/mprotect.c:1008 page last free pid 5173 tgid 5173 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:2906 __slab_free+0x2c6/0x370 mm/slub.c:5962 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:352 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 getname_flags+0xb8/0x540 fs/namei.c:146 getname include/linux/fs.h:2922 [inline] do_sys_openat2+0xbc/0x1c0 fs/open.c:1431 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 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: ffff888030fd9300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888030fd9380: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff888030fd9400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888030fd9480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888030fd9500: 00 00 00 00 00 00 00 00 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 c0 f4 b8 ff call 0xffb8f4dc 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