syz.4.769: attempt to access beyond end of device loop4: rw=524288, sector=88, nr_sectors = 48 limit=16 syz.4.769: attempt to access beyond end of device loop4: 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 ffff0000d1c54000 by task syz.4.769/6950 CPU: 1 PID: 6950 Comm: syz.4.769 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+0x152c/0x16cc fs/erofs/zdata.c:1603 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_cow_fault mm/memory.c:4659 [inline] do_fault mm/memory.c:4760 [inline] handle_pte_fault mm/memory.c:5029 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x18b4/0x2fb0 mm/memory.c:5292 faultin_page mm/gup.c:1026 [inline] __get_user_pages+0x33c/0x754 mm/gup.c:1250 populate_vma_page_range+0x1f4/0x298 mm/gup.c:1607 __mm_populate+0x210/0x334 mm/gup.c:1721 mm_populate include/linux/mm.h:2891 [inline] vm_mmap_pgoff+0x1d8/0x294 mm/util.c:525 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+0x98/0x290 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 6449: 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 do_mas_align_munmap+0x1c0/0xf38 mm/mmap.c:2453 do_mas_munmap mm/mmap.c:2650 [inline] __vm_munmap+0x25c/0x38c mm/mmap.c:2936 __do_sys_munmap mm/mmap.c:2961 [inline] __se_sys_munmap mm/mmap.c:2958 [inline] __arm64_sys_munmap+0x64/0x7c mm/mmap.c:2958 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 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 6449: 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_bulk+0x33c/0x3d0 mm/slub.c:3805 mt_free_bulk lib/maple_tree.c:164 [inline] mas_destroy+0x1bfc/0x22dc lib/maple_tree.c:5864 mas_store_prealloc+0x284/0x354 lib/maple_tree.c:5792 do_mas_align_munmap+0x948/0xf38 mm/mmap.c:2574 do_mas_munmap mm/mmap.c:2650 [inline] __vm_munmap+0x25c/0x38c mm/mmap.c:2936 __do_sys_munmap mm/mmap.c:2961 [inline] __se_sys_munmap mm/mmap.c:2958 [inline] __arm64_sys_munmap+0x64/0x7c mm/mmap.c:2958 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 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 ffff0000d1c54000 which belongs to the cache maple_node of size 256 The buggy address is located 0 bytes inside of 256-byte region [ffff0000d1c54000, ffff0000d1c54100) The buggy address belongs to the physical page: page:0000000069611c3c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111c54 head:0000000069611c3c order:1 compound_mapcount:0 compound_pincount:0 flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000010200 0000000000000000 dead000000000122 ffff0000c000d680 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000d1c53f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000d1c53f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000d1c54000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000d1c54080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000d1c54100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== syz.4.769: attempt to access beyond end of device loop4: rw=0, sector=16, nr_sectors = 8 limit=16 syz.4.769: attempt to access beyond end of device loop4: rw=0, sector=16, nr_sectors = 8 limit=16 syz.4.769: attempt to access beyond end of device loop4: rw=0, sector=16, nr_sectors = 8 limit=16 syz.4.769: attempt to access beyond end of device loop4: rw=0, sector=16, nr_sectors = 8 limit=16