loop7: rw=524288, sector=1056, nr_sectors = 16 limit=16 syz.7.3098: attempt to access beyond end of device loop7: rw=524288, sector=8, nr_sectors = 16 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 ffff0000da008000 by task syz.7.3098/17238 CPU: 1 PID: 17238 Comm: syz.7.3098 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_update_page mm/filemap.c:2575 [inline] filemap_get_pages mm/filemap.c:2689 [inline] filemap_read+0x12cc/0x2104 mm/filemap.c:2759 generic_file_read_iter+0xf8/0x5c4 mm/filemap.c:2941 call_read_iter include/linux/fs.h:2259 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x3d4/0x7f0 fs/read_write.c:470 ksys_read+0x12c/0x224 fs/read_write.c:613 __do_sys_read fs/read_write.c:623 [inline] __se_sys_read fs/read_write.c:621 [inline] __arm64_sys_read+0x7c/0x90 fs/read_write.c:621 __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 17125: 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 __vma_adjust+0x25c/0x1724 mm/mmap.c:724 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] __vm_munmap+0x25c/0x38c mm/mmap.c:2936 vm_munmap+0x2c/0x3c mm/mmap.c:2954 elf_map+0x148/0x224 fs/binfmt_elf.c:373 load_elf_interp+0x3c4/0x924 fs/binfmt_elf.c:664 load_elf_binary+0x124c/0x1b5c fs/binfmt_elf.c:1272 search_binary_handler fs/exec.c:1764 [inline] exec_binprm fs/exec.c:1805 [inline] bprm_execve+0x804/0x1558 fs/exec.c:1874 kernel_execve+0x6c0/0x7b8 fs/exec.c:2039 call_usermodehelper_exec_async+0x1f8/0x39c kernel/umh.c:113 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 Freed by task 17125: 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 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] __vm_munmap+0x25c/0x38c mm/mmap.c:2936 vm_munmap+0x2c/0x3c mm/mmap.c:2954 elf_map+0x148/0x224 fs/binfmt_elf.c:373 load_elf_interp+0x3c4/0x924 fs/binfmt_elf.c:664 load_elf_binary+0x124c/0x1b5c fs/binfmt_elf.c:1272 search_binary_handler fs/exec.c:1764 [inline] exec_binprm fs/exec.c:1805 [inline] bprm_execve+0x804/0x1558 fs/exec.c:1874 kernel_execve+0x6c0/0x7b8 fs/exec.c:2039 call_usermodehelper_exec_async+0x1f8/0x39c kernel/umh.c:113 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 The buggy address belongs to the object at ffff0000da008000 which belongs to the cache maple_node of size 256 The buggy address is located 0 bytes inside of 256-byte region [ffff0000da008000, ffff0000da008100) The buggy address belongs to the physical page: page:000000008706ce41 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11a008 head:000000008706ce41 order:1 compound_mapcount:0 compound_pincount:0 flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000010200 fffffc0003397b80 dead000000000002 ffff0000c000d680 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000da007f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000da007f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000da008000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000da008080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000da008100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== syz.7.3098: attempt to access beyond end of device loop7: rw=0, sector=1056, nr_sectors = 8 limit=16