loop8: rw=524288, sector=88, nr_sectors = 48 limit=16 syz.8.1000: attempt to access beyond end of device loop8: rw=524288, sector=8, nr_sectors = 80 limit=16 ================================================================== BUG: KASAN: use-after-free in memcpy_to_page include/linux/highmem.h:403 [inline] BUG: KASAN: use-after-free in z_erofs_transform_plain+0x3a4/0x490 fs/erofs/decompressor.c:346 Read of size 4096 at addr ffff0000ed452000 by task syz.8.1000/9637 CPU: 1 PID: 9637 Comm: syz.8.1000 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call trace: dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 print_address_description+0x88/0x218 mm/kasan/report.c:316 print_report+0x50/0x68 mm/kasan/report.c:420 kasan_report+0xa8/0xfc mm/kasan/report.c:524 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x258/0x290 mm/kasan/generic.c:189 memcpy+0x48/0x90 mm/kasan/shadow.c:65 memcpy_to_page include/linux/highmem.h:403 [inline] z_erofs_transform_plain+0x3a4/0x490 fs/erofs/decompressor.c:346 z_erofs_decompress+0x9c/0xd4 fs/erofs/decompressor.c:434 z_erofs_decompress_pcluster fs/erofs/zdata.c:1159 [inline] z_erofs_decompress_queue+0x100c/0x1b40 fs/erofs/zdata.c:1240 z_erofs_runqueue+0x1564/0x16cc fs/erofs/zdata.c:-1 z_erofs_read_folio+0x2d8/0x5c8 fs/erofs/zdata.c:1693 filemap_read_folio+0x134/0x384 mm/filemap.c:2490 filemap_fault+0x98c/0xe98 mm/filemap.c:3340 __do_fault+0x11c/0x3d8 mm/memory.c:4278 do_read_fault mm/memory.c:4629 [inline] do_fault mm/memory.c:4758 [inline] handle_pte_fault mm/memory.c:5029 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x1cac/0x2fb0 mm/memory.c:5292 __do_page_fault arch/arm64/mm/fault.c:499 [inline] do_page_fault+0x310/0x98c arch/arm64/mm/fault.c:583 do_translation_fault+0x94/0xc8 arch/arm64/mm/fault.c:667 do_mem_abort+0x70/0x194 arch/arm64/mm/fault.c:804 el1_abort+0x3c/0x5c arch/arm64/kernel/entry-common.c:367 el1h_64_sync_handler+0x50/0xac arch/arm64/kernel/entry-common.c:427 el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:580 do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] strncpy_from_user+0x25c/0x578 lib/strncpy_from_user.c:139 getname_flags+0xec/0x45c fs/namei.c:150 getname+0x28/0x38 fs/namei.c:218 do_sys_openat2+0xdc/0x3f4 fs/open.c:1314 do_sys_open fs/open.c:1336 [inline] __do_sys_openat fs/open.c:1352 [inline] __se_sys_openat fs/open.c:1347 [inline] __arm64_sys_openat+0x118/0x14c fs/open.c:1347 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Allocated by task 9573: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:53 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x70/0x88 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x74/0x430 mm/slab.h:737 kmem_cache_alloc_bulk+0x41c/0x4e4 mm/slub.c:3880 mt_alloc_bulk lib/maple_tree.c:159 [inline] mas_alloc_nodes+0x484/0x754 lib/maple_tree.c:1301 mas_node_count_gfp lib/maple_tree.c:1361 [inline] mas_preallocate+0x13c/0x310 lib/maple_tree.c:5809 __mmap_region mm/mmap.c:2765 [inline] mmap_region+0xc4c/0x1900 mm/mmap.c:2916 do_mmap+0x9cc/0x1138 mm/mmap.c:1436 vm_mmap_pgoff+0x190/0x294 mm/util.c:520 ksys_mmap_pgoff+0x3b8/0x5a0 mm/mmap.c:1482 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline] __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline] __arm64_sys_mmap+0xf8/0x110 arch/arm64/kernel/sys.c:21 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Freed by task 21: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:53 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:516 ____kasan_slab_free+0x148/0x1b0 mm/kasan/common.c:237 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:245 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x16c/0x1e8 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] kmem_cache_free+0x118/0x314 mm/slub.c:3709 mt_free_rcu+0x28/0x38 lib/maple_tree.c:171 rcu_do_batch kernel/rcu/tree.c:2297 [inline] rcu_core+0x828/0x18b0 kernel/rcu/tree.c:2557 rcu_core_si+0x10/0x1c kernel/rcu/tree.c:2574 handle_softirqs+0x318/0xc60 kernel/softirq.c:596 run_ksoftirqd+0x7c/0x2ac kernel/softirq.c:968 smpboot_thread_fn+0x4b0/0x964 kernel/smpboot.c:164 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 Last potentially related work creation: kasan_save_stack+0x40/0x70 mm/kasan/common.c:46 __kasan_record_aux_stack+0xc0/0xdc mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:496 call_rcu+0x100/0x94c kernel/rcu/tree.c:2849 ma_free_rcu lib/maple_tree.c:184 [inline] mas_free lib/maple_tree.c:1343 [inline] mas_replace+0x5f0/0xa14 lib/maple_tree.c:1782 mas_commit_b_node lib/maple_tree.c:3664 [inline] mas_wr_bnode lib/maple_tree.c:4385 [inline] mas_wr_modify+0x3530/0x41cc lib/maple_tree.c:4428 mas_wr_store_entry+0x754/0xb28 lib/maple_tree.c:4465 mas_store_prealloc+0x240/0x354 lib/maple_tree.c:5790 vma_mas_store+0x194/0x430 mm/mmap.c:434 __vma_adjust+0xf18/0x1724 mm/mmap.c:832 vma_adjust include/linux/mm.h:2810 [inline] __split_vma+0x324/0x444 mm/mmap.c:-1 do_mas_align_munmap+0x2ec/0xf38 mm/mmap.c:2480 do_mas_munmap mm/mmap.c:2650 [inline] __mmap_region mm/mmap.c:2698 [inline] mmap_region+0x780/0x1900 mm/mmap.c:2916 do_mmap+0x9cc/0x1138 mm/mmap.c:1436 vm_mmap_pgoff+0x190/0x294 mm/util.c:520 ksys_mmap_pgoff+0x3b8/0x5a0 mm/mmap.c:1482 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline] __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline] __arm64_sys_mmap+0xf8/0x110 arch/arm64/kernel/sys.c:21 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 The buggy address belongs to the object at ffff0000ed452000 which belongs to the cache maple_node of size 256 The buggy address is located 0 bytes inside of 256-byte region [ffff0000ed452000, ffff0000ed452100) The buggy address belongs to the physical page: page:0000000000053d85 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12d452 head:0000000000053d85 order:1 compound_mapcount:0 compound_pincount:0 flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000010200 dead000000000100 dead000000000122 ffff0000c000d680 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000ed451f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000ed451f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000ed452000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000ed452080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000ed452100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================