================================================================== BUG: KASAN: slab-use-after-free in ocfs2_fault+0xd3/0x3e0 fs/ocfs2/mmap.c:41 Read of size 8 at addr ffff8880506e4e18 by task syz.6.320/7377 CPU: 1 UID: 0 PID: 7377 Comm: syz.6.320 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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+0xd3/0x3e0 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+0x2206/0x3330 mm/memory.c:4401 handle_pte_fault mm/memory.c:6273 [inline] __handle_mm_fault mm/memory.c:6411 [inline] handle_mm_fault+0x1b26/0x32b0 mm/memory.c:6580 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x1650/0x29f0 mm/gup.c:1428 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1860 __mm_populate+0x24c/0x380 mm/gup.c:1963 mm_populate include/linux/mm.h:3701 [inline] vm_mmap_pgoff+0x387/0x4d0 mm/util.c:586 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f555e98f749 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:00007f555f791038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f555ebe5fa0 RCX: 00007f555e98f749 RDX: 00000000027ffff7 RSI: 0000000000600000 RDI: 0000200000000000 RBP: 00007f555ea13f91 R08: 0000000000000004 R09: 0000000000004000 R10: 0000000004012011 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f555ebe6038 R14: 00007f555ebe5fa0 R15: 00007ffe85280498 Allocated by task 7377: 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:339 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x37d/0x710 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+0xdea/0x1d10 mm/vma.c:2786 do_mmap+0xc45/0x10d0 mm/mmap.c:558 vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:581 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 15: 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:584 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:2540 [inline] slab_free_after_rcu_debug+0x125/0x260 mm/slub.c:6727 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xd70/0x1870 kernel/rcu/tree.c:2857 handle_softirqs+0x27d/0x850 kernel/softirq.c:622 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1063 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 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:56 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 slab_free_hook mm/slub.c:2501 [inline] slab_free mm/slub.c:6668 [inline] kmem_cache_free+0x475/0x620 mm/slub.c:6779 remove_vma mm/vma.c:462 [inline] vms_complete_munmap_vmas+0x626/0x8a0 mm/vma.c:1296 __mmap_complete+0x7b/0x610 mm/vma.c:2540 __mmap_region mm/vma.c:2717 [inline] mmap_region+0x11e3/0x1d10 mm/vma.c:2786 do_mmap+0xc45/0x10d0 mm/mmap.c:558 vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:581 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880506e4dc0 which belongs to the cache vm_area_struct of size 256 The buggy address is located 88 bytes inside of freed 256-byte region [ffff8880506e4dc0, ffff8880506e4ec0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x506e4 memcg:ffff88804fcf9781 anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801aabbb40 0000000000000000 dead000000000001 raw: 0000000000000000 00000000000c000c 00000000f5000000 ffff88804fcf9781 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 6555, tgid 6555 (sed), ts 156067078981, free_ts 155703661773 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210 alloc_pages_mpol+0x232/0x4a0 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+0xf2b/0x1960 mm/slub.c:4656 __kmem_cache_alloc_bulk+0x1d9/0x550 mm/slub.c:7429 refill_sheaf mm/slub.c:2650 [inline] __pcs_replace_empty_main+0x298/0x560 mm/slub.c:5023 alloc_from_pcs mm/slub.c:5121 [inline] slab_alloc_node mm/slub.c:5248 [inline] kmem_cache_alloc_noprof+0x469/0x710 mm/slub.c:5270 vm_area_dup+0x2b/0x680 mm/vma_init.c:123 __split_vma+0x1a9/0xa00 mm/vma.c:508 vms_gather_munmap_vmas+0x2e2/0x12f0 mm/vma.c:1362 __mmap_setup mm/vma.c:2366 [inline] __mmap_region mm/vma.c:2690 [inline] mmap_region+0x72b/0x1d10 mm/vma.c:2786 do_mmap+0xc45/0x10d0 mm/mmap.c:558 vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:581 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604 page last free pid 470 tgid 470 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc8/0xd30 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+0xd70/0x1870 kernel/rcu/tree.c:2857 handle_softirqs+0x27d/0x850 kernel/softirq.c:622 do_softirq+0xec/0x180 kernel/softirq.c:523 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] __alloc_skb+0x224/0x430 net/core/skbuff.c:674 alloc_skb include/linux/skbuff.h:1383 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:818 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:875 [inline] nsim_dev_trap_report_work+0x29a/0xb80 drivers/net/netdevsim/dev.c:921 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 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: ffff8880506e4d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880506e4d80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff8880506e4e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880506e4e80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8880506e4f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================