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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 ffff0000e8de5000 by task syz.1.511/7760

CPU: 0 PID: 7760 Comm: syz.1.511 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/23/2026
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:1612
 z_erofs_read_folio+0x2dc/0x5cc fs/erofs/zdata.c:1702
 filemap_read_folio+0x134/0x384 mm/filemap.c:2490
 filemap_fault+0x990/0xe98 mm/filemap.c:3340
 __do_fault+0x11c/0x3d8 mm/memory.c:4278
 do_read_fault mm/memory.c:4629 [inline]
 do_fault mm/memory.c:4758 [inline]
 handle_pte_fault mm/memory.c:5029 [inline]
 __handle_mm_fault mm/memory.c:5171 [inline]
 handle_mm_fault+0x1d04/0x3018 mm/memory.c:5292
 __do_page_fault arch/arm64/mm/fault.c:499 [inline]
 do_page_fault+0x310/0x99c arch/arm64/mm/fault.c:583
 do_translation_fault+0x94/0xc8 arch/arm64/mm/fault.c:667
 do_mem_abort+0x70/0x198 arch/arm64/mm/fault.c:804
 el1_abort+0x48/0x6c arch/arm64/kernel/entry-common.c:367
 el1h_64_sync_handler+0x50/0xac arch/arm64/kernel/entry-common.c:427
 el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:580
 __arch_copy_from_user+0x1b4/0x230 arch/arm64/lib/copy_template.S:164
 __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+0x58/0x12c 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 6323:
 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_dup+0x30/0x1c4 kernel/fork.c:468
 dup_mmap kernel/fork.c:647 [inline]
 dup_mm kernel/fork.c:1552 [inline]
 copy_mm+0x828/0x1208 kernel/fork.c:1601
 copy_process+0x16d8/0x38b4 kernel/fork.c:2358
 kernel_clone+0x1ec/0x938 kernel/fork.c:2765
 __do_sys_clone kernel/fork.c:2906 [inline]
 __se_sys_clone kernel/fork.c:2874 [inline]
 __arm64_sys_clone+0x15c/0x1c8 kernel/fork.c:2874
 __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+0x58/0x12c 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 ffff0000e8de5000
 which belongs to the cache vm_area_struct of size 152
The buggy address is located 0 bytes inside of
 152-byte region [ffff0000e8de5000, ffff0000e8de5098)

The buggy address belongs to the physical page:
page:0000000033539c6e refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x128de5
memcg:ffff0000d829da01
flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000200 fffffc0003f78c00 dead00000000000b ffff0000c03df680
raw: 0000000000000000 0000000000120012 00000001ffffffff ffff0000d829da01
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000e8de4f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000e8de5000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000e8de5080: 00 00 00 fc fc fc fc fc fc fc fc 00 00 00 00 00
                            ^
 ffff0000e8de5100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc
 ffff0000e8de5180: fc fc fc fc fc fc 00 00 00 00 00 00 00 00 00 00
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