loop3: rw=524288, sector=34359738360, nr_sectors = 8 limit=16
syz.3.85: attempt to access beyond end of device
loop3: rw=524288, sector=8, nr_sectors = 16 limit=16
==================================================================
BUG: KASAN: slab-out-of-bounds in memcpy_to_page include/linux/highmem.h:403 [inline]
BUG: KASAN: slab-out-of-bounds in z_erofs_transform_plain+0x39c/0x494 fs/erofs/decompressor.c:347
Read of size 4096 at addr ffff0000caffc000 by task syz.3.85/4702

CPU: 1 PID: 4702 Comm: syz.3.85 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026
Call trace:
 dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106
 print_address_description+0x88/0x218 mm/kasan/report.c:316
 print_report+0x50/0x68 mm/kasan/report.c:420
 kasan_report+0xa8/0xfc mm/kasan/report.c:524
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x258/0x290 mm/kasan/generic.c:189
 memcpy+0x48/0x90 mm/kasan/shadow.c:65
 memcpy_to_page include/linux/highmem.h:403 [inline]
 z_erofs_transform_plain+0x39c/0x494 fs/erofs/decompressor.c:347
 z_erofs_decompress+0x9c/0xd4 fs/erofs/decompressor.c:435
 z_erofs_decompress_pcluster fs/erofs/zdata.c:1159 [inline]
 z_erofs_decompress_queue+0x103c/0x1bf4 fs/erofs/zdata.c:1240
 z_erofs_runqueue+0x1508/0x16a8 fs/erofs/zdata.c:1603
 z_erofs_read_folio+0x2dc/0x5cc fs/erofs/zdata.c:1693
 filemap_read_folio+0x134/0x384 mm/filemap.c:2490
 filemap_update_page mm/filemap.c:2575 [inline]
 filemap_get_pages mm/filemap.c:2689 [inline]
 filemap_read+0x1290/0x20dc mm/filemap.c:2759
 generic_file_read_iter+0xf8/0x5ac mm/filemap.c:2941
 call_read_iter include/linux/fs.h:2259 [inline]
 new_sync_read fs/read_write.c:389 [inline]
 vfs_read+0x3cc/0x7b8 fs/read_write.c:470
 ksys_read+0x12c/0x228 fs/read_write.c:613
 __do_sys_read fs/read_write.c:623 [inline]
 __se_sys_read fs/read_write.c:621 [inline]
 __arm64_sys_read+0x7c/0x90 fs/read_write.c:621
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

Allocated by task 1:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4c/0x80 mm/kasan/common.c:53
 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:505
 __kasan_slab_alloc+0x70/0x88 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x74/0x430 mm/slab.h:737
 slab_alloc_node mm/slub.c:3359 [inline]
 slab_alloc mm/slub.c:3367 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3374 [inline]
 kmem_cache_alloc+0x234/0x310 mm/slub.c:3383
 vm_area_alloc+0x2c/0xe8 kernel/fork.c:460
 __mmap_region mm/mmap.c:2753 [inline]
 mmap_region+0xb38/0x1860 mm/mmap.c:2916
 do_mmap+0xa64/0x1210 mm/mmap.c:1436
 vm_mmap_pgoff+0x194/0x298 mm/util.c:520
 ksys_mmap_pgoff+0x364/0x5a0 mm/mmap.c:1482
 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline]
 __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline]
 __arm64_sys_mmap+0x108/0x120 arch/arm64/kernel/sys.c:21
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

The buggy address belongs to the object at ffff0000caffc000
 which belongs to the cache vm_area_struct of size 152
The buggy address is located 0 bytes inside of
 152-byte region [ffff0000caffc000, ffff0000caffc098)

The buggy address belongs to the physical page:
page:0000000049bdc02c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10affc
flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000200 fffffc00036209c0 dead000000000008 ffff0000c03df680
raw: 0000000000000000 0000000000120012 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000caffbf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000caffc000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000caffc080: 00 00 00 fc fc fc fc fc fc fc fc 00 00 00 00 00
                            ^
 ffff0000caffc100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc
 ffff0000caffc180: fc fc fc fc fc fc 00 00 00 00 00 00 00 00 00 00
==================================================================
syz.3.85: attempt to access beyond end of device
loop3: rw=0, sector=34359738360, nr_sectors = 8 limit=16