syz.1.2: attempt to access beyond end of device loop1: rw=524288, sector=16, nr_sectors = 8 limit=16 syz.1.2: attempt to access beyond end of device loop1: 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 ffff88801e789400 by task syz.1.2/5873 CPU: 1 PID: 5873 Comm: syz.1.2 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: 0033:0x7f8cded8e929 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:00007f8cdfc39038 EFLAGS: 00000246 ORIG_RAX: 00000000000000dd RAX: ffffffffffffffda RBX: 00007f8cdefb6080 RCX: 00007f8cded8e929 RDX: 000000000000ff39 RSI: 000000000000aa1f RDI: 0000000000000004 RBP: 00007f8cdee10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8cdefb6080 R15: 00007ffe29a2dd08 The buggy address belongs to the physical page: page:ffffea000079e240 refcount:2 mapcount:0 mapping:ffff88805da587c8 index:0x1 pfn:0x1e789 memcg:ffff88801b7f6000 aops:z_erofs_cache_aops ino:0 flags: 0xfff40000008028(uptodate|lru|private|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff40000008028 ffffea0000bdd688 ffffea0000b801c8 ffff88805da587c8 raw: 0000000000000001 ffff88805da84000 00000002ffffffff ffff88801b7f6000 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 5869, tgid 5867 (syz.1.2), ts 74772686225, free_ts 74683760197 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+0x32/0x2e0 mm/page_alloc.c:2429 __slab_free+0x35e/0x410 mm/slub.c:3722 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3485 [inline] slab_alloc mm/slub.c:3493 [inline] __kmem_cache_alloc_lru mm/slub.c:3500 [inline] kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509 getname_flags+0xbb/0x500 fs/namei.c:140 user_path_at_empty+0x2c/0x60 fs/namei.c:2908 user_path_at include/linux/namei.h:57 [inline] __do_sys_chroot fs/open.c:599 [inline] __se_sys_chroot+0x94/0x3b0 fs/open.c:593 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: ffff88801e789f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88801e789f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88801e78a000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801e78a080: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88801e78a100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================