loop0: rw=524288, sector=88, nr_sectors = 48 limit=16 syz.0.1010: attempt to access beyond end of device loop0: rw=524288, sector=8, nr_sectors = 80 limit=16 ================================================================== BUG: KASAN: slab-out-of-bounds in memcpy_to_page include/linux/highmem.h:403 [inline] BUG: KASAN: slab-out-of-bounds in z_erofs_transform_plain+0x39c/0x494 fs/erofs/decompressor.c:347 Read of size 4096 at addr ffff0000cb924000 by task syz.0.1010/7443 CPU: 1 PID: 7443 Comm: syz.0.1010 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026 Call trace: dump_backtrace+0x1c4/0x1f0 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+0x39c/0x494 fs/erofs/decompressor.c:347 z_erofs_decompress+0x9c/0xd4 fs/erofs/decompressor.c:435 z_erofs_decompress_pcluster fs/erofs/zdata.c:1159 [inline] z_erofs_decompress_queue+0x103c/0x1bf4 fs/erofs/zdata.c:1240 z_erofs_runqueue+0x1540/0x16a8 fs/erofs/zdata.c:-1 z_erofs_read_folio+0x2dc/0x5cc fs/erofs/zdata.c:1693 filemap_read_folio+0x134/0x384 mm/filemap.c:2490 filemap_fault+0x990/0xe98 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+0x1d04/0x3018 mm/memory.c:5292 __do_page_fault arch/arm64/mm/fault.c:499 [inline] do_page_fault+0x310/0x99c arch/arm64/mm/fault.c:583 do_translation_fault+0x94/0xc8 arch/arm64/mm/fault.c:667 do_mem_abort+0x70/0x198 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+0x264/0x59c lib/strncpy_from_user.c:139 getname_flags+0xec/0x458 fs/namei.c:150 getname+0x28/0x38 fs/namei.c:218 do_sys_openat2+0xdc/0x3fc 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+0x11c/0x150 fs/open.c:1347 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 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 4334: 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 slab_alloc_node mm/slub.c:3359 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc+0x234/0x310 mm/slub.c:3383 anon_vma_chain_alloc mm/rmap.c:141 [inline] anon_vma_clone+0x8c/0x44c mm/rmap.c:287 anon_vma_fork+0x7c/0x45c mm/rmap.c:350 dup_mmap kernel/fork.c:669 [inline] dup_mm kernel/fork.c:1548 [inline] copy_mm+0x8d0/0x1208 kernel/fork.c:1597 copy_process+0x1718/0x38f4 kernel/fork.c:2358 kernel_clone+0x1ec/0x938 kernel/fork.c:2765 __do_sys_clone kernel/fork.c:2906 [inline] __se_sys_clone kernel/fork.c:2874 [inline] __arm64_sys_clone+0x15c/0x1c8 kernel/fork.c:2874 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 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 ffff0000cb924000 which belongs to the cache anon_vma_chain of size 80 The buggy address is located 0 bytes inside of 80-byte region [ffff0000cb924000, ffff0000cb924050) The buggy address belongs to the physical page: page:00000000725e1d9b refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10b924 memcg:ffff0000f5dec401 flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000200 fffffc00030eb840 dead000000000005 ffff0000c03dec00 raw: 0000000000000000 0000000080240024 00000001ffffffff ffff0000f5dec401 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000cb923f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000cb923f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000cb924000: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc 00 00 ^ ffff0000cb924080: 00 00 00 00 00 00 00 00 fc fc fc fc 00 00 00 00 ffff0000cb924100: 00 00 00 00 00 00 fc fc fc fc 00 00 00 00 00 00 ==================================================================