loop0: rw=524288, sector=16, nr_sectors = 8 limit=16 syz.0.1393: attempt to access beyond end of device loop0: rw=524288, sector=13716630376, nr_sectors = 8 limit=16 ================================================================== BUG: KASAN: slab-out-of-bounds in memcpy_to_page include/linux/highmem.h:427 [inline] BUG: KASAN: slab-out-of-bounds in z_erofs_transform_plain+0x38c/0x460 fs/erofs/decompressor.c:346 Read of size 4095 at addr ffff88807e6c5400 by task syz.0.1393/11440 CPU: 0 PID: 11440 Comm: syz.0.1393 Not tainted 6.6.94-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xac/0x230 mm/kasan/report.c:475 kasan_report+0x117/0x150 mm/kasan/report.c:588 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x288/0x290 mm/kasan/generic.c:187 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105 memcpy_to_page include/linux/highmem.h:427 [inline] z_erofs_transform_plain+0x38c/0x460 fs/erofs/decompressor.c:346 z_erofs_decompress_pcluster fs/erofs/zdata.c:1290 [inline] z_erofs_decompress_queue+0x16fb/0x2650 fs/erofs/zdata.c:1371 z_erofs_runqueue+0x18a3/0x19d0 fs/erofs/zdata.c:1759 z_erofs_readahead+0xa7c/0xd50 fs/erofs/zdata.c:1888 read_pages+0x177/0x840 mm/readahead.c:160 page_cache_ra_unbounded+0x692/0x770 mm/readahead.c:269 do_page_cache_ra mm/readahead.c:299 [inline] force_page_cache_ra+0x2c1/0x320 mm/readahead.c:330 force_page_cache_readahead mm/internal.h:175 [inline] generic_fadvise+0x44f/0x730 mm/fadvise.c:106 vfs_fadvise mm/fadvise.c:185 [inline] ksys_fadvise64_64 mm/fadvise.c:199 [inline] __do_sys_fadvise64 mm/fadvise.c:214 [inline] __se_sys_fadvise64 mm/fadvise.c:212 [inline] __x64_sys_fadvise64+0x140/0x180 mm/fadvise.c:212 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f0e2178e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0e2251f038 EFLAGS: 00000246 ORIG_RAX: 00000000000000dd RAX: ffffffffffffffda RBX: 00007f0e219b6080 RCX: 00007f0e2178e929 RDX: 000000000000ff39 RSI: 000000000000aa1f RDI: 0000000000000006 RBP: 00007f0e21810b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f0e219b6080 R15: 00007ffe38dff2d8 The buggy address belongs to the physical page: page:ffffea0001f9b140 refcount:2 mapcount:0 mapping:ffff888058831278 index:0x1 pfn:0x7e6c5 memcg:ffff88807d4a2000 aops:z_erofs_cache_aops ino:0 flags: 0xfff40000008028(uptodate|lru|private|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff40000008028 ffffea0001855588 ffffea0000afc308 ffff888058831278 raw: 0000000000000001 ffff888077ed9028 00000002ffffffff ffff88807d4a2000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x192840(GFP_NOWAIT|__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 11437, tgid 11436 (syz.0.1393), ts 914922834570, free_ts 914917512761 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457 z_erofs_bind_cache fs/erofs/zdata.c:599 [inline] z_erofs_pcluster_begin fs/erofs/zdata.c:883 [inline] z_erofs_do_read_page+0x20c0/0x3680 fs/erofs/zdata.c:1018 z_erofs_read_folio+0x213/0x540 fs/erofs/zdata.c:1839 filemap_read_folio+0x167/0x760 mm/filemap.c:2420 do_read_cache_folio+0x470/0x7e0 mm/filemap.c:3789 erofs_bread+0x16f/0x630 fs/erofs/data.c:48 erofs_find_target_block fs/erofs/namei.c:103 [inline] erofs_namei+0x28c/0xf00 fs/erofs/namei.c:177 erofs_lookup+0x135/0x310 fs/erofs/namei.c:206 __lookup_slow+0x281/0x3b0 fs/namei.c:1694 lookup_slow+0x53/0x70 fs/namei.c:1711 walk_component+0x2be/0x3f0 fs/namei.c:2002 lookup_last fs/namei.c:2459 [inline] path_lookupat+0x169/0x440 fs/namei.c:2483 filename_lookup+0x1f4/0x510 fs/namei.c:2512 user_path_at_empty+0x42/0x60 fs/namei.c:2909 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1154 [inline] free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429 tlb_batch_list_free mm/mmu_gather.c:114 [inline] tlb_finish_mmu+0x112/0x1d0 mm/mmu_gather.c:395 exit_mmap+0x3f0/0xb50 mm/mmap.c:3305 __mmput+0x118/0x3c0 kernel/fork.c:1355 exit_mm+0x1da/0x2c0 kernel/exit.c:569 do_exit+0x886/0x23c0 kernel/exit.c:861 do_group_exit+0x21b/0x2d0 kernel/exit.c:1023 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Memory state around the buggy address: ffff88807e6c5f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88807e6c6000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88807e6c6080: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ^ ffff88807e6c6100: fc fc 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88807e6c6180: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ==================================================================