================================================================== BUG: KASAN: slab-use-after-free in ma_data_end lib/maple_tree.c:1255 [inline] BUG: KASAN: slab-use-after-free in mtree_range_walk+0x604/0x8d0 lib/maple_tree.c:2556 Read of size 8 at addr a8f000000d211e78 by task syz.0.309/4424 Pointer tag: [a8], memory tag: [fe] CPU: 0 UID: 0 PID: 4424 Comm: syz.0.309 Not tainted syzkaller #0 PREEMPT Hardware name: linux,dummy-virt (DT) Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 print_address_description+0xac/0x288 mm/kasan/report.c:378 print_report+0x84/0xa0 mm/kasan/report.c:482 kasan_report+0xb0/0x110 mm/kasan/report.c:595 kasan_tag_mismatch+0x28/0x3c mm/kasan/sw_tags.c:176 __hwasan_tag_mismatch+0x30/0x60 arch/arm64/lib/kasan_sw_tags.S:55 ma_data_end lib/maple_tree.c:1255 [inline] mtree_range_walk+0x604/0x8d0 lib/maple_tree.c:2556 mas_state_walk lib/maple_tree.c:3296 [inline] mas_walk+0xf8/0x34c lib/maple_tree.c:4597 lock_vma_under_rcu+0x10c/0x35c mm/mmap_lock.c:232 do_page_fault+0x3a8/0x1508 arch/arm64/mm/fault.c:625 do_translation_fault+0xbc/0xfc arch/arm64/mm/fault.c:789 do_mem_abort+0x50/0x110 arch/arm64/mm/fault.c:929 el0_da+0x64/0x210 arch/arm64/kernel/entry-common.c:562 el0t_64_sync_handler+0x90/0x12c arch/arm64/kernel/entry-common.c:768 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 Allocated by task 4430: kasan_save_stack+0x40/0x6c mm/kasan/common.c:56 save_stack_info+0x30/0x138 mm/kasan/tags.c:106 kasan_save_alloc_info+0x14/0x20 mm/kasan/tags.c:142 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x94/0x98 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4970 [inline] slab_alloc_node mm/slub.c:5280 [inline] kmem_cache_alloc_noprof+0x320/0x5a8 mm/slub.c:5287 mt_alloc_one lib/maple_tree.c:172 [inline] mas_alloc_nodes+0x350/0x3b8 lib/maple_tree.c:1108 mas_preallocate+0x544/0x970 lib/maple_tree.c:5192 vma_iter_prealloc mm/vma.h:442 [inline] __split_vma+0x318/0xb00 mm/vma.c:528 vms_gather_munmap_vmas+0x2d4/0x1474 mm/vma.c:1359 do_vmi_align_munmap+0x174/0x280 mm/vma.c:1527 do_vmi_munmap+0x1ac/0x210 mm/vma.c:1584 __vm_munmap+0x1a8/0x2e8 mm/vma.c:3156 __do_sys_munmap mm/mmap.c:1080 [inline] __se_sys_munmap mm/mmap.c:1077 [inline] __arm64_sys_munmap+0x78/0xa4 mm/mmap.c:1077 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x90/0x238 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x180/0x2f4 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x58/0x74 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x234 arch/arm64/kernel/entry-common.c:746 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 Freed by task 4425: kasan_save_stack+0x40/0x6c mm/kasan/common.c:56 save_stack_info+0x30/0x138 mm/kasan/tags.c:106 __kasan_save_free_info+0x18/0x24 mm/kasan/tags.c:147 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x64/0x68 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2539 [inline] __rcu_free_sheaf_prepare+0x11c/0x2c4 mm/slub.c:2745 rcu_free_sheaf+0x2c/0x138 mm/slub.c:6181 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xe14/0x1d30 kernel/rcu/tree.c:2861 rcu_core_si+0x10/0x1c kernel/rcu/tree.c:2878 handle_softirqs+0x36c/0xd08 kernel/softirq.c:622 __do_softirq+0x14/0x20 kernel/softirq.c:656 The buggy address belongs to the object at fff000000d211e00 which belongs to the cache maple_node of size 256 The buggy address is located 120 bytes inside of 256-byte region [fff000000d211e00, fff000000d211f00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xa8f000000d211e00 pfn:0x4d211 flags: 0x1ffc00000000200(workingset|node=0|zone=0|lastcpupid=0x7ff|kasantag=0x0) page_type: f5(slab) raw: 01ffc00000000200 01f000000cc09700 ffffc1ffc046a910 ffffc1ffc0573d90 raw: a8f000000d211e00 000000000010000f 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: fff000000d211c00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fff000000d211d00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe >fff000000d211e00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe ^ fff000000d211f00: 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 fff000000d212000: 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 ==================================================================