================================================================== 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 ffff88802e0e8418 by task syz.0.2312/18158 CPU: 1 UID: 0 PID: 18158 Comm: syz.0.2312 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: 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: 0033:0x7f2a6498ebe9 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:00007f2a657c4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000019 RAX: ffffffffffffffda RBX: 00007f2a64bb6090 RCX: 00007f2a6498ebe9 RDX: 0000000000002000 RSI: 0000000000002000 RDI: 0000200000ffc000 RBP: 00007f2a64a11e19 R08: 0000200000fff000 R09: 0000000000000000 R10: 0000000000000007 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2a64bb6128 R14: 00007f2a64bb6090 R15: 00007ffd2aaf2ad8 Allocated by task 12754: 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_dup+0x2b/0x680 mm/vma_init.c:122 dup_mmap+0x90c/0x1ac0 mm/mmap.c:1780 dup_mm kernel/fork.c:1485 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1537 copy_process+0x1706/0x3c00 kernel/fork.c:2175 kernel_clone+0x21e/0x840 kernel/fork.c:2605 __do_sys_clone kernel/fork.c:2748 [inline] __se_sys_clone kernel/fork.c:2732 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2732 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 12: 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 ffff88802e0e83c0 which belongs to the cache vm_area_struct of size 256 The buggy address is located 88 bytes inside of freed 256-byte region [ffff88802e0e83c0, ffff88802e0e84c0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2e0e8 memcg:ffff88804c3ad381 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801bad5b40 dead000000000100 dead000000000122 raw: 0000000000000000 00000000000c000c 00000000f5000000 ffff88804c3ad381 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 16025, tgid 16025 (modprobe), ts 496911916475, free_ts 491030375953 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 ksys_mmap_pgoff+0x51f/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 page last free pid 15818 tgid 15818 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 vfree+0x25a/0x400 mm/vmalloc.c:3434 vb2_vmalloc_put+0x68/0xb0 drivers/media/common/videobuf2/videobuf2-vmalloc.c:68 __vb2_buf_mem_free+0x119/0x2d0 drivers/media/common/videobuf2/videobuf2-core.c:275 __vb2_free_mem drivers/media/common/videobuf2/videobuf2-core.c:571 [inline] __vb2_queue_free+0x414/0xb00 drivers/media/common/videobuf2/videobuf2-core.c:599 vb2_core_queue_release+0x6b/0x150 drivers/media/common/videobuf2/videobuf2-core.c:2695 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:956 [inline] _vb2_fop_release drivers/media/common/videobuf2/videobuf2-v4l2.c:1154 [inline] vb2_fop_release+0x16e/0x200 drivers/media/common/videobuf2/videobuf2-v4l2.c:1168 v4l2_release+0x250/0x370 drivers/media/v4l2-core/v4l2-dev.c:471 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:961 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 __do_sys_exit_group kernel/exit.c:1113 [inline] __se_sys_exit_group kernel/exit.c:1111 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232 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: ffff88802e0e8300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802e0e8380: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff88802e0e8400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802e0e8480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88802e0e8500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================