loop1: rw=524288, sector=1056, nr_sectors = 16 limit=16
syz.1.2: attempt to access beyond end of device
loop1: rw=524288, sector=8, nr_sectors = 16 limit=16
==================================================================
BUG: KASAN: use-after-free in memcpy_to_page include/linux/highmem.h:403 [inline]
BUG: KASAN: use-after-free in z_erofs_transform_plain+0x3a4/0x490 fs/erofs/decompressor.c:346
Read of size 4096 at addr ffff0000f6951000 by task syz.1.2/4440

CPU: 1 PID: 4440 Comm: syz.1.2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026
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_read_folio+0x2d8/0x5c8 fs/erofs/zdata.c:1687
 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+0x12cc/0x2104 mm/filemap.c:2759
 generic_file_read_iter+0xf8/0x5c4 mm/filemap.c:2941
 call_read_iter include/linux/fs.h:2259 [inline]
 new_sync_read fs/read_write.c:389 [inline]
 vfs_read+0x3d4/0x7f0 fs/read_write.c:470
 ksys_read+0x12c/0x224 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+0x98/0x2b4 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:00000000e8921a31 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x136951
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffc0003da5488 fffffc0003464a88 0000000000000000
raw: 0000000000000000 ffff0000c863da20 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000f6950f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000f6950f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000f6951000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff0000f6951080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000f6951100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
syz.1.2: attempt to access beyond end of device
loop1: rw=0, sector=1056, nr_sectors = 8 limit=16