syz.1.288: attempt to access beyond end of device loop1: rw=524288, sector=16, nr_sectors = 8 limit=16 syz.1.288: attempt to access beyond end of device loop1: rw=524288, sector=13716630376, nr_sectors = 8 limit=16 ================================================================== BUG: KASAN: use-after-free in z_erofs_transform_plain+0x37a/0x490 fs/erofs/decompressor.c:350 Read of size 4095 at addr ffff888076fbb400 by task syz.1.288/5663 CPU: 0 PID: 5663 Comm: syz.1.288 Not tainted 6.1.141-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x220 mm/kasan/report.c:427 kasan_report+0x10b/0x140 mm/kasan/report.c:531 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x27b/0x290 mm/kasan/generic.c:189 memcpy+0x25/0x60 mm/kasan/shadow.c:65 z_erofs_transform_plain+0x37a/0x490 fs/erofs/decompressor.c:350 z_erofs_decompress_pcluster fs/erofs/zdata.c:1175 [inline] z_erofs_decompress_queue+0x1577/0x2370 fs/erofs/zdata.c:1258 z_erofs_runqueue+0x1a83/0x1bc0 fs/erofs/zdata.c:1616 z_erofs_readahead+0xa36/0xdc0 fs/erofs/zdata.c:1760 read_pages+0x173/0x840 mm/readahead.c:161 page_cache_ra_unbounded+0x690/0x770 mm/readahead.c:270 do_page_cache_ra mm/readahead.c:300 [inline] force_page_cache_ra+0x2bd/0x320 mm/readahead.c:331 force_page_cache_readahead mm/internal.h:125 [inline] generic_fadvise+0x44e/0x6c0 mm/fadvise.c:107 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+0x139/0x180 mm/fadvise.c:212 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f45d658e929 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:00007f45d742b038 EFLAGS: 00000246 ORIG_RAX: 00000000000000dd RAX: ffffffffffffffda RBX: 00007f45d67b5fa0 RCX: 00007f45d658e929 RDX: 000000000000ff39 RSI: 000000000000aa1f RDI: 0000000000000004 RBP: 00007f45d6610b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f45d67b5fa0 R15: 00007ffc030fc448 The buggy address belongs to the physical page: page:ffffea0001dbeec0 refcount:2 mapcount:0 mapping:ffff8880712197d0 index:0x1 pfn:0x76fbb memcg:ffff88807e61a000 aops:managed_cache_aops ino:0 flags: 0xfff40000002014(uptodate|lru|private|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff40000002014 ffffea000098fa08 ffffea0001494e88 ffff8880712197d0 raw: 0000000000000001 ffff8880743b6000 00000002ffffffff ffff88807e61a000 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 5663, tgid 5662 (syz.1.288), ts 266095797903, free_ts 265479925182 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614 z_erofs_bind_cache fs/erofs/zdata.c:482 [inline] z_erofs_do_read_page+0x19be/0x39e0 fs/erofs/zdata.c:860 z_erofs_read_folio+0x256/0x5c0 fs/erofs/zdata.c:1705 filemap_read_folio+0x160/0x760 mm/filemap.c:2490 do_read_cache_folio+0x2a0/0x760 mm/filemap.c:3627 erofs_bread+0x18e/0x670 fs/erofs/data.c:50 erofs_find_target_block fs/erofs/namei.c:102 [inline] erofs_namei+0x28f/0xf00 fs/erofs/namei.c:175 erofs_lookup+0x14b/0x390 fs/erofs/namei.c:204 __lookup_slow+0x27d/0x3a0 fs/namei.c:1690 lookup_slow+0x53/0x70 fs/namei.c:1707 walk_component fs/namei.c:1998 [inline] link_path_walk+0x928/0xe50 fs/namei.c:2325 path_openat+0x276/0x2e70 fs/namei.c:3779 do_filp_open+0x1c1/0x3c0 fs/namei.c:3810 do_sys_openat2+0x142/0x490 fs/open.c:1318 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384 free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3525 release_pages+0x1f92/0x2200 mm/swap.c:1035 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline] tlb_flush_mmu_free mm/mmu_gather.c:254 [inline] tlb_flush_mmu+0xff/0x210 mm/mmu_gather.c:261 tlb_finish_mmu+0xbd/0x1c0 mm/mmu_gather.c:361 exit_mmap+0x343/0x8e0 mm/mmap.c:3250 __mmput+0x118/0x3c0 kernel/fork.c:1200 exit_mm+0x1e6/0x2c0 kernel/exit.c:565 do_exit+0x8b9/0x2400 kernel/exit.c:858 do_group_exit+0x217/0x2d0 kernel/exit.c:1021 get_signal+0x1272/0x1350 kernel/signal.c:2871 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871 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:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 Memory state around the buggy address: ffff888076fbbf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888076fbbf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888076fbc000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888076fbc080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888076fbc100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================