loop3: rw=524288, sector=720, nr_sectors = 16 limit=16 syz.3.856: attempt to access beyond end of device loop3: rw=524288, sector=525144, nr_sectors = 16 limit=16 syz.3.856: attempt to access beyond end of device loop3: rw=524288, sector=16, nr_sectors = 8 limit=16 syz.3.856: attempt to access beyond end of device loop3: rw=524288, sector=13716630376, nr_sectors = 8 limit=16 ================================================================== BUG: KASAN: slab-use-after-free in memcpy_to_page include/linux/highmem.h:427 [inline] BUG: KASAN: slab-use-after-free in z_erofs_transform_plain+0x38c/0x460 fs/erofs/decompressor.c:346 Read of size 4095 at addr ffff888077bfd400 by task syz.3.856/9942 CPU: 0 PID: 9942 Comm: syz.3.856 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: 0033:0x7f862838e929 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:00007f8629264038 EFLAGS: 00000246 ORIG_RAX: 00000000000000dd RAX: ffffffffffffffda RBX: 00007f86285b5fa0 RCX: 00007f862838e929 RDX: 000000000000ff39 RSI: 000000000000aa1f RDI: 0000000000000006 RBP: 00007f8628410b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f86285b5fa0 R15: 00007ffda3f16688 The buggy address belongs to the physical page: page:ffffea0001deff40 refcount:2 mapcount:0 mapping:ffff88805b530270 index:0x1 pfn:0x77bfd memcg:ffff88807d2b4000 aops:z_erofs_cache_aops ino:0 flags: 0xfff40000008028(uptodate|lru|private|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff40000008028 ffffea000199f108 ffffea0000bcc2c8 ffff88805b530270 raw: 0000000000000001 ffff88805cc9a000 00000002ffffffff ffff88807d2b4000 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 9942, tgid 9941 (syz.3.856), ts 576043884226, free_ts 573538509499 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 fs/namei.c:2002 [inline] link_path_walk+0x970/0xe00 fs/namei.c:2329 path_openat+0x283/0x3190 fs/namei.c:3785 do_filp_open+0x1c5/0x3d0 fs/namei.c:3816 do_sys_openat2+0x12c/0x1c0 fs/open.c:1419 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_list+0xbe/0x860 mm/page_alloc.c:2475 release_pages+0x1fa0/0x2220 mm/swap.c:1022 tlb_batch_pages_flush mm/mmu_gather.c:98 [inline] tlb_flush_mmu_free mm/mmu_gather.c:293 [inline] tlb_flush_mmu+0x368/0x4f0 mm/mmu_gather.c:300 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:392 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 __do_sys_exit_group kernel/exit.c:1034 [inline] __se_sys_exit_group kernel/exit.c:1032 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1032 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 Memory state around the buggy address: ffff888077bfdf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888077bfdf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888077bfe000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888077bfe080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ffff888077bfe100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ==================================================================