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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 4095 at addr ffff0000cd26a400 by task syz.1.349/6464

CPU: 0 PID: 6464 Comm: syz.1.349 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
Call trace:
 dump_backtrace+0x1c8/0x1f4 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+0xf8/0x160 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+0xa8/0x100 mm/kasan/report.c:524
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x260/0x2a0 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+0x1054/0x1b94 fs/erofs/zdata.c:1240
 z_erofs_runqueue+0x14c0/0x1620 fs/erofs/zdata.c:1606
 z_erofs_read_folio+0x2bc/0x594 fs/erofs/zdata.c:1687
 filemap_read_folio+0x130/0x37c mm/filemap.c:2490
 do_read_cache_folio+0x24c/0x544 mm/filemap.c:3627
 read_cache_folio+0x68/0x88 mm/filemap.c:3659
 erofs_bread+0x13c/0x520 fs/erofs/data.c:50
 erofs_find_target_block fs/erofs/namei.c:102 [inline]
 erofs_namei+0x1fc/0xc00 fs/erofs/namei.c:175
 erofs_lookup+0x158/0x450 fs/erofs/namei.c:204
 lookup_open fs/namei.c:3468 [inline]
 open_last_lookups fs/namei.c:3558 [inline]
 path_openat+0xfa4/0x2680 fs/namei.c:3788
 do_filp_open+0x174/0x344 fs/namei.c:3818
 do_sys_openat2+0x128/0x3d8 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __arm64_sys_openat+0x120/0x154 fs/open.c:1345
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x138 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:00000000c18ef255 refcount:2 mapcount:0 mapping:00000000e6a12d20 index:0x1 pfn:0x10d26a
memcg:ffff0000cd708000
aops:managed_cache_aops ino:0
flags: 0x5ffd00000002014(uptodate|lru|private|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffd00000002014 fffffc0003614388 fffffc0003d29f88 ffff0000f6e29278
raw: 0000000000000001 ffff0000dea09270 00000002ffffffff ffff0000cd708000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000cd26af00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000cd26af80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000cd26b000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff0000cd26b080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
 ffff0000cd26b100: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
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