================================================================== BUG: KASAN: slab-out-of-bounds in z_erofs_transform_plain+0x37a/0x490 fs/erofs/decompressor.c:350 Read of size 4095 at addr ffff888057b8a400 by task syz.4.22/4468 CPU: 1 PID: 4468 Comm: syz.4.22 Not tainted 6.1.144-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+0x1aae/0x1bc0 fs/erofs/zdata.c:1625 z_erofs_read_folio+0x336/0x5c0 fs/erofs/zdata.c:1711 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+0x2be/0x3f0 fs/namei.c:1998 lookup_last fs/namei.c:2455 [inline] path_lookupat+0x169/0x440 fs/namei.c:2479 filename_lookup+0x1f0/0x500 fs/namei.c:2508 user_path_at_empty+0x3e/0x60 fs/namei.c:2905 user_path_at include/linux/namei.h:57 [inline] __do_sys_chdir fs/open.c:514 [inline] __se_sys_chdir+0x91/0x280 fs/open.c:508 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: 0033:0x7f6481b8e929 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:00007f64819de038 EFLAGS: 00000246 ORIG_RAX: 0000000000000050 RAX: ffffffffffffffda RBX: 00007f6481db6080 RCX: 00007f6481b8e929 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00002000000001c0 RBP: 00007f6481c10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6481db6080 R15: 00007ffc4a697be8 The buggy address belongs to the physical page: page:ffffea00015ee280 refcount:2 mapcount:0 mapping:ffff888070e007c8 index:0x1 pfn:0x57b8a memcg:ffff88807d806000 aops:managed_cache_aops ino:0 flags: 0xfff40000002014(uptodate|lru|private|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff40000002014 ffffea00015eed08 ffffea0000629148 ffff888070e007c8 raw: 0000000000000001 ffff888070dbc000 00000002ffffffff ffff88807d806000 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 4468, tgid 4464 (syz.4.22), ts 87305921059, free_ts 87234946615 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+0x2be/0x3f0 fs/namei.c:1998 lookup_last fs/namei.c:2455 [inline] path_lookupat+0x169/0x440 fs/namei.c:2479 filename_lookup+0x1f0/0x500 fs/namei.c:2508 user_path_at_empty+0x3e/0x60 fs/namei.c:2905 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+0x2e/0x3f0 mm/page_alloc.c:3479 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x123/0x2f0 mm/slub.c:3422 getname_flags+0xb7/0x500 fs/namei.c:139 user_path_at_empty+0x28/0x60 fs/namei.c:2904 do_readlinkat+0xd4/0x480 fs/stat.c:468 __do_sys_readlink fs/stat.c:501 [inline] __se_sys_readlink fs/stat.c:498 [inline] __x64_sys_readlink+0x7b/0x90 fs/stat.c:498 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 Memory state around the buggy address: ffff888057b8af00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888057b8af80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888057b8b000: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc ^ ffff888057b8b080: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ffff888057b8b100: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================