================================================================== BUG: KASAN: slab-use-after-free in ma_dead_node lib/maple_tree.c:575 [inline] BUG: KASAN: slab-use-after-free in mas_rewalk_if_dead lib/maple_tree.c:4415 [inline] BUG: KASAN: slab-use-after-free in mas_next_slot+0x185/0xcf0 lib/maple_tree.c:4697 Read of size 8 at addr ffff888031ce0000 by task syz.1.2149/17945 CPU: 1 UID: 0 PID: 17945 Comm: syz.1.2149 Not tainted 6.16.0-rc6-next-20250714-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x230 mm/kasan/report.c:480 kasan_report+0x118/0x150 mm/kasan/report.c:593 ma_dead_node lib/maple_tree.c:575 [inline] mas_rewalk_if_dead lib/maple_tree.c:4415 [inline] mas_next_slot+0x185/0xcf0 lib/maple_tree.c:4697 mas_find+0xb0e/0xd30 lib/maple_tree.c:6062 vma_find include/linux/mm.h:855 [inline] remap_move mm/mremap.c:1819 [inline] do_mremap mm/mremap.c:1904 [inline] __do_sys_mremap mm/mremap.c:1968 [inline] __se_sys_mremap+0xaff/0xef0 mm/mremap.c:1936 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: 0033:0x7fe9c038e929 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:00007fe9c11ca038 EFLAGS: 00000246 ORIG_RAX: 0000000000000019 RAX: ffffffffffffffda RBX: 00007fe9c05b6080 RCX: 00007fe9c038e929 RDX: 0000000000600002 RSI: 0000000000600002 RDI: 0000200000000000 RBP: 00007fe9c0410b39 R08: 0000200000a00000 R09: 0000000000000000 R10: 0000000000000007 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fe9c05b6080 R15: 00007ffcc63f3458 Allocated by task 17941: 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:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 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 mt_alloc_one lib/maple_tree.c:176 [inline] mas_alloc_nodes+0x2e9/0x8e0 lib/maple_tree.c:1255 mas_node_count_gfp lib/maple_tree.c:1337 [inline] mas_preallocate+0x3ad/0x6f0 lib/maple_tree.c:5537 vma_iter_prealloc mm/vma.h:463 [inline] __split_vma+0x2fa/0xa00 mm/vma.c:528 vms_gather_munmap_vmas+0x2de/0x12b0 mm/vma.c:1359 __mmap_prepare mm/vma.c:2361 [inline] __mmap_region mm/vma.c:2653 [inline] mmap_region+0x724/0x20c0 mm/vma.c:2741 do_mmap+0xc45/0x10d0 mm/mmap.c:561 vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:579 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 17941: 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:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kmem_cache_free+0x18f/0x400 mm/slub.c:4782 rcu_do_batch kernel/rcu/tree.c:2584 [inline] rcu_core+0xca8/0x1710 kernel/rcu/tree.c:2840 handle_softirqs+0x283/0x870 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:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 __call_rcu_common kernel/rcu/tree.c:3102 [inline] call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3222 mas_wr_node_store lib/maple_tree.c:3893 [inline] mas_wr_store_entry+0x1f1b/0x25b0 lib/maple_tree.c:4104 mas_store_prealloc+0xb00/0xf60 lib/maple_tree.c:5510 vma_iter_store_new mm/vma.h:509 [inline] vma_complete+0x224/0xae0 mm/vma.c:354 __split_vma+0x8a6/0xa00 mm/vma.c:568 vms_gather_munmap_vmas+0x2de/0x12b0 mm/vma.c:1359 do_vmi_align_munmap+0x25d/0x420 mm/vma.c:1527 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1584 do_munmap+0xe1/0x140 mm/mmap.c:1071 mremap_to+0x304/0x7b0 mm/mremap.c:1367 remap_move mm/mremap.c:1861 [inline] do_mremap mm/mremap.c:1904 [inline] __do_sys_mremap mm/mremap.c:1968 [inline] __se_sys_mremap+0xa0b/0xef0 mm/mremap.c:1936 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 ffff888031ce0000 which belongs to the cache maple_node of size 256 The buggy address is located 0 bytes inside of freed 256-byte region [ffff888031ce0000, ffff888031ce0100) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x31ce0 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801a491000 ffffea00008ae380 dead000000000004 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801a491000 ffffea00008ae380 dead000000000004 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffea0000c73801 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x52800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP), pid 5226, tgid 5226 (udevd), ts 41134650190, free_ts 39834768992 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 __kmem_cache_alloc_bulk mm/slub.c:5331 [inline] kmem_cache_alloc_bulk_noprof+0x20e/0x790 mm/slub.c:5403 mt_alloc_bulk lib/maple_tree.c:181 [inline] mas_alloc_nodes+0x447/0x8e0 lib/maple_tree.c:1277 mas_node_count_gfp lib/maple_tree.c:1337 [inline] mas_node_count lib/maple_tree.c:1351 [inline] mas_wr_preallocate lib/maple_tree.c:4292 [inline] mas_insert+0x3ec/0x690 lib/maple_tree.c:4325 mas_alloc_cyclic+0x20e/0x630 lib/maple_tree.c:4388 mtree_alloc_cyclic+0x186/0x220 lib/maple_tree.c:6527 simple_offset_add+0xdc/0x190 fs/libfs.c:297 shmem_mknod+0x234/0x3e0 mm/shmem.c:3871 lookup_open fs/namei.c:3708 [inline] open_last_lookups fs/namei.c:3807 [inline] path_openat+0x14f1/0x3830 fs/namei.c:4043 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 page last free pid 15 tgid 15 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 rcu_do_batch kernel/rcu/tree.c:2584 [inline] rcu_core+0xca8/0x1710 kernel/rcu/tree.c:2840 handle_softirqs+0x283/0x870 kernel/softirq.c:579 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:160 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888031cdff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888031cdff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888031ce0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888031ce0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888031ce0100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================