loop0: rw=524288, sector=16, nr_sectors = 8 limit=16
syz.0.77: attempt to access beyond end of device
loop0: rw=524288, sector=13716630376, nr_sectors = 8 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+0x3a4/0x490 fs/erofs/decompressor.c:346
Read of size 4095 at addr ffff0000ce8f2400 by task syz.0.77/4684

CPU: 0 PID: 4684 Comm: syz.0.77 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
Call trace:
 dump_backtrace+0x1c0/0x1ec 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+0x3a4/0x490 fs/erofs/decompressor.c:346
 z_erofs_decompress+0x9c/0xd4 fs/erofs/decompressor.c:434
 z_erofs_decompress_pcluster fs/erofs/zdata.c:1159 [inline]
 z_erofs_decompress_queue+0x100c/0x1b40 fs/erofs/zdata.c:1240
 z_erofs_runqueue+0x14d4/0x1694 fs/erofs/zdata.c:1597
 z_erofs_readahead+0x84c/0xbf4 fs/erofs/zdata.c:1733
 read_pages+0x158/0x680 mm/readahead.c:161
 page_cache_ra_unbounded+0x490/0x574 mm/readahead.c:270
 do_page_cache_ra mm/readahead.c:300 [inline]
 force_page_cache_ra+0x248/0x2b0 mm/readahead.c:331
 force_page_cache_readahead mm/internal.h:125 [inline]
 generic_fadvise+0x340/0x5b8 mm/fadvise.c:107
 vfs_fadvise mm/fadvise.c:185 [inline]
 ksys_fadvise64_64 mm/fadvise.c:199 [inline]
 __do_sys_fadvise64_64 mm/fadvise.c:207 [inline]
 __se_sys_fadvise64_64 mm/fadvise.c:205 [inline]
 __arm64_sys_fadvise64_64+0x12c/0x174 mm/fadvise.c:205
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x130 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 physical page:
page:0000000005e3163d refcount:2 mapcount:0 mapping:0000000032dbb4dd index:0x1 pfn:0x10e8f2
memcg:ffff0000cbff4000
aops:managed_cache_aops ino:0
flags: 0x5ffd00000002014(uptodate|lru|private|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffd00000002014 fffffc0003d66b88 fffffc0003714f08 ffff0000e23187c8
raw: 0000000000000001 ffff0000e0707000 00000002ffffffff ffff0000cbff4000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000ce8f2f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000ce8f2f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000ce8f3000: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                         ^
 ffff0000ce8f3080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000ce8f3100: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================