================================================================== BUG: KASAN: slab-use-after-free in ocfs2_fault+0xd3/0x400 fs/ocfs2/mmap.c:41 Read of size 8 at addr ffff888033774418 by task syz.1.27/6096 CPU: 1 UID: 0 PID: 6096 Comm: syz.1.27 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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+0x135/0x390 mm/memory.c:5152 do_read_fault mm/memory.c:5573 [inline] do_fault mm/memory.c:5707 [inline] do_pte_missing mm/memory.c:4234 [inline] handle_pte_fault mm/memory.c:6052 [inline] __handle_mm_fault mm/memory.c:6195 [inline] handle_mm_fault+0x23c6/0x3400 mm/memory.c:6364 faultin_page mm/gup.c:1144 [inline] __get_user_pages+0x16e4/0x2b60 mm/gup.c:1446 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1880 __mm_populate+0x24c/0x380 mm/gup.c:1983 mm_populate include/linux/mm.h:3367 [inline] vm_mmap_pgoff+0x38a/0x4d0 mm/util.c:585 ksys_mmap_pgoff+0x4e9/0x720 mm/mmap.c:604 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f00d5edeba9 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:00007f00d411d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f00d6126090 RCX: 00007f00d5edeba9 RDX: 00000000027ffff7 RSI: 0000000000600000 RDI: 0000200000000000 RBP: 00007f00d5f61e19 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000004012011 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f00d6126128 R14: 00007f00d6126090 R15: 00007fffbb0751e8 Allocated by task 6096: 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:330 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:356 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4191 [inline] slab_alloc_node mm/slub.c:4240 [inline] kmem_cache_alloc_noprof+0x143/0x310 mm/slub.c:4247 vm_area_alloc+0x24/0x140 mm/vma_init.c:31 __mmap_new_vma mm/vma.c:2461 [inline] __mmap_region mm/vma.c:2669 [inline] mmap_region+0xdd2/0x20a0 mm/vma.c:2739 do_mmap+0xc23/0x10c0 mm/mmap.c:558 vm_mmap_pgoff+0x2a9/0x4d0 mm/util.c:580 ksys_mmap_pgoff+0x4e9/0x720 mm/mmap.c:604 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 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: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:243 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2422 [inline] slab_free_after_rcu_debug+0x129/0x3c0 mm/slub.c:4745 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core kernel/rcu/tree.c:2861 [inline] rcu_cpu_kthread+0xbf3/0x1b50 kernel/rcu/tree.c:2949 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:160 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 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+0xbd/0xd0 mm/kasan/generic.c:548 slab_free_hook mm/slub.c:2383 [inline] slab_free mm/slub.c:4695 [inline] kmem_cache_free+0x3ef/0x510 mm/slub.c:4797 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:2677 [inline] mmap_region+0x11e9/0x20a0 mm/vma.c:2739 do_mmap+0xc23/0x10c0 mm/mmap.c:558 vm_mmap_pgoff+0x2a9/0x4d0 mm/util.c:580 ksys_mmap_pgoff+0x4e9/0x720 mm/mmap.c:604 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880337743c0 which belongs to the cache vm_area_struct of size 256 The buggy address is located 88 bytes inside of freed 256-byte region [ffff8880337743c0, ffff8880337744c0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x33774 memcg:ffff88802fb41b01 flags: 0x80000000000000(node=0|zone=1) page_type: f5(slab) raw: 0080000000000000 ffff88801aeceb40 dead000000000100 dead000000000122 raw: 0000000000000000 00000000000c000c 00000000f5000000 ffff88802fb41b01 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 5692, tgid 5692 (sftp-server), ts 77426757960, free_ts 39310137658 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x2119/0x21b0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2492 [inline] allocate_slab+0x8a/0x370 mm/slub.c:2660 new_slab mm/slub.c:2714 [inline] ___slab_alloc+0x8d1/0xdc0 mm/slub.c:3901 __slab_alloc mm/slub.c:3992 [inline] __slab_alloc_node mm/slub.c:4067 [inline] slab_alloc_node mm/slub.c:4228 [inline] kmem_cache_alloc_noprof+0xe6/0x310 mm/slub.c:4247 vm_area_dup+0x2b/0x670 mm/vma_init.c:122 __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+0x8cd/0xce0 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 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 5219 tgid 5219 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xb59/0xce0 mm/page_alloc.c:2895 discard_slab mm/slub.c:2758 [inline] __put_partials+0x159/0x1a0 mm/slub.c:3223 __slab_free+0x2b3/0x390 mm/slub.c:4565 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:340 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4191 [inline] slab_alloc_node mm/slub.c:4240 [inline] __do_kmalloc_node mm/slub.c:4375 [inline] __kmalloc_noprof+0x1a5/0x430 mm/slub.c:4388 kmalloc_noprof include/linux/slab.h:909 [inline] kernfs_fop_write_iter+0x159/0x540 fs/kernfs/file.c:329 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5d5/0xb40 fs/read_write.c:686 ksys_write+0x14b/0x260 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888033774300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888033774380: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff888033774400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888033774480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888033774500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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