================================================================== BUG: KASAN: slab-use-after-free in ocfs2_fault+0xdb/0x440 fs/ocfs2/mmap.c:41 Read of size 8 at addr ffff88805e362e18 by task syz.1.1354/17175 CPU: 1 UID: 0 PID: 17175 Comm: syz.1.1354 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:do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] RIP: 0010:strncpy_from_user+0xb7/0x2b0 lib/strncpy_from_user.c:130 Code: 00 00 4c 89 f6 e8 b9 38 eb fc 49 83 fe 07 0f 86 9d 00 00 00 48 89 1c 24 4c 89 74 24 08 48 c7 c5 f8 ff ff ff 45 31 ff 4c 89 e3 <4f> 8b 34 3c 48 b8 ff fe fe fe fe fe fe fe 4d 8d 24 06 4d 89 f5 49 RSP: 0018:ffffc9000713fd98 EFLAGS: 00050246 RAX: ffffffff84d91fd7 RBX: 00002000000001c0 RCX: ffff88801dbadac0 RDX: 0000000000000002 RSI: 00000000000000a8 RDI: 0000000000000007 RBP: fffffffffffffff8 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed1009adf9f8 R12: 00002000000001c0 R13: 00002000000001c0 R14: 00000000000000a8 R15: 0000000000000000 do_getname+0x77/0x250 fs/namei.c:193 getname include/linux/fs.h:2512 [inline] class_filename_constructor include/linux/fs.h:2539 [inline] do_sys_truncate+0xa0/0x1c0 fs/open.c:138 __do_sys_truncate fs/open.c:154 [inline] __se_sys_truncate fs/open.c:152 [inline] __x64_sys_truncate+0x5b/0x70 fs/open.c:152 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: 0033:0x7fd21854c799 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:00007fd21675c028 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007fd2187c6180 RCX: 00007fd21854c799 RDX: 0000000000000000 RSI: 00000000000042dc RDI: 00002000000001c0 RBP: 00007fd2185e2bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd2187c6218 R14: 00007fd2187c6180 R15: 00007fff37b0d698 Allocated by task 17170: 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:4515 [inline] slab_alloc_node mm/slub.c:4844 [inline] kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4851 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:2692 [inline] slab_free_after_rcu_debug+0x126/0x220 mm/slub.c:6208 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:2653 [inline] slab_free mm/slub.c:6143 [inline] kmem_cache_free+0x4fb/0x6b0 mm/slub.c:6273 remove_vma mm/vma.c:470 [inline] vms_complete_munmap_vmas+0x929/0xc60 mm/vma.c:1342 __mmap_complete+0x7b/0x5e0 mm/vma.c:2588 __mmap_region mm/vma.c:2768 [inline] mmap_region+0x15ed/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 The buggy address belongs to the object at ffff88805e362dc0 which belongs to the cache vm_area_struct of size 256 The buggy address is located 88 bytes inside of freed 256-byte region [ffff88805e362dc0, ffff88805e362ec0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5e362 memcg:ffff88805e362f01 flags: 0x80000000000000(node=0|zone=1) page_type: f5(slab) raw: 0080000000000000 ffff888140412500 dead000000000100 dead000000000122 raw: 0000000000000000 00000008000c000c 00000000f5000000 ffff88805e362f01 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 15259, tgid 15259 (cmp), ts 796803809365, free_ts 796801752174 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:3269 [inline] allocate_slab+0x77/0x660 mm/slub.c:3458 new_slab mm/slub.c:3516 [inline] refill_objects+0x334/0x3c0 mm/slub.c:7153 refill_sheaf mm/slub.c:2818 [inline] __pcs_replace_empty_main+0x328/0x5f0 mm/slub.c:4592 alloc_from_pcs mm/slub.c:4695 [inline] slab_alloc_node mm/slub.c:4829 [inline] kmem_cache_alloc_noprof+0x433/0x680 mm/slub.c:4851 vm_area_dup+0x2b/0x670 mm/vma_init.c:123 __split_vma+0x1e4/0xa30 mm/vma.c:513 vms_gather_munmap_vmas+0x4fa/0x1370 mm/vma.c:1429 __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 28 tgid 28 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 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 Memory state around the buggy address: ffff88805e362d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805e362d80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff88805e362e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805e362e80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88805e362f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 4c 89 f6 mov %r14,%rsi 5: e8 b9 38 eb fc call 0xfceb38c3 a: 49 83 fe 07 cmp $0x7,%r14 e: 0f 86 9d 00 00 00 jbe 0xb1 14: 48 89 1c 24 mov %rbx,(%rsp) 18: 4c 89 74 24 08 mov %r14,0x8(%rsp) 1d: 48 c7 c5 f8 ff ff ff mov $0xfffffffffffffff8,%rbp 24: 45 31 ff xor %r15d,%r15d 27: 4c 89 e3 mov %r12,%rbx * 2a: 4f 8b 34 3c mov (%r12,%r15,1),%r14 <-- trapping instruction 2e: 48 b8 ff fe fe fe fe movabs $0xfefefefefefefeff,%rax 35: fe fe fe 38: 4d 8d 24 06 lea (%r14,%rax,1),%r12 3c: 4d 89 f5 mov %r14,%r13 3f: 49 rex.WB