==================================================================
BUG: KASAN: slab-use-after-free in vma_multi_allowed mm/mremap.c:1623 [inline]
BUG: KASAN: slab-use-after-free in remap_move mm/mremap.c:1884 [inline]
BUG: KASAN: slab-use-after-free in do_mremap mm/mremap.c:1923 [inline]
BUG: KASAN: slab-use-after-free in __do_sys_mremap mm/mremap.c:1987 [inline]
BUG: KASAN: slab-use-after-free in __se_sys_mremap+0xb33/0x1150 mm/mremap.c:1955
Read of size 8 at addr ffff888073ca4058 by task syz.1.300/7398

CPU: 0 UID: 0 PID: 7398 Comm: syz.1.300 Not tainted 6.17.0-rc1-next-20250814-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 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
 vma_multi_allowed mm/mremap.c:1623 [inline]
 remap_move mm/mremap.c:1884 [inline]
 do_mremap mm/mremap.c:1923 [inline]
 __do_sys_mremap mm/mremap.c:1987 [inline]
 __se_sys_mremap+0xb33/0x1150 mm/mremap.c:1955
 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: 0033:0x7f232638ebe9
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:00007f23271b3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000019
RAX: ffffffffffffffda RBX: 00007f23265b6270 RCX: 00007f232638ebe9
RDX: 0000000000600000 RSI: 0000000000600000 RDI: 0000200000000000
RBP: 00007f2326411e19 R08: 0000200000a00000 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f23265b6308 R14: 00007f23265b6270 R15: 00007ffe8e09e828
 </TASK>

Allocated by task 7398:
 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:250 [inline]
 slab_post_alloc_hook mm/slub.c:4180 [inline]
 slab_alloc_node mm/slub.c:4229 [inline]
 kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4236
 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+0xdc7/0x20c0 mm/vma.c:2739
 do_mmap+0xc45/0x10d0 mm/mmap.c:558
 vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:580
 ksys_mmap_pgoff+0x587/0x760 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 7369:
 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+0x5b/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2417 [inline]
 slab_free_after_rcu_debug+0x129/0x2a0 mm/slub.c:4730
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core+0xca8/0x1770 kernel/rcu/tree.c:2861
 handle_softirqs+0x286/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

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:2378 [inline]
 slab_free mm/slub.c:4680 [inline]
 kmem_cache_free+0x2f6/0x400 mm/slub.c:4782
 remove_vma mm/vma.c:468 [inline]
 vms_complete_munmap_vmas+0x626/0x8a0 mm/vma.c:1293
 do_vmi_align_munmap+0x358/0x420 mm/vma.c:1536
 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1584
 do_munmap+0xe1/0x140 mm/mmap.c:1068
 mremap_to+0x2df/0x7a0 mm/mremap.c:1372
 remap_move mm/mremap.c:1879 [inline]
 do_mremap mm/mremap.c:1923 [inline]
 __do_sys_mremap mm/mremap.c:1987 [inline]
 __se_sys_mremap+0xadf/0x1150 mm/mremap.c:1955
 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 ffff888073ca4000
 which belongs to the cache vm_area_struct of size 256
The buggy address is located 88 bytes inside of
 freed 256-byte region [ffff888073ca4000, ffff888073ca4100)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x73ca4
memcg:ffff888031b71a01
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801bad5b40 ffffea00016db900 dead000000000008
raw: 0000000000000000 00000000000c000c 00000000f5000000 ffff888031b71a01
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 6812, tgid 6812 (modprobe), ts 138964058712, free_ts 138944885531
 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+0x21e4/0x22c0 mm/page_alloc.c:3858
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:2487 [inline]
 allocate_slab+0x8a/0x370 mm/slub.c:2655
 new_slab mm/slub.c:2709 [inline]
 ___slab_alloc+0xbeb/0x1410 mm/slub.c:3891
 __slab_alloc mm/slub.c:3981 [inline]
 __slab_alloc_node mm/slub.c:4056 [inline]
 slab_alloc_node mm/slub.c:4217 [inline]
 kmem_cache_alloc_noprof+0x283/0x3c0 mm/slub.c:4236
 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+0xdc7/0x20c0 mm/vma.c:2739
 do_mmap+0xc45/0x10d0 mm/mmap.c:558
 vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:580
 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 154 tgid 154 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895
 pagetable_free include/linux/mm.h:2917 [inline]
 pagetable_dtor_free include/linux/mm.h:3015 [inline]
 __tlb_remove_table+0x2d2/0x3b0 include/asm-generic/tlb.h:220
 __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+0xca8/0x1770 kernel/rcu/tree.c:2861
 handle_softirqs+0x286/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

Memory state around the buggy address:
 ffff888073ca3f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888073ca3f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888073ca4000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff888073ca4080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888073ca4100: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
==================================================================