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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+0x3a4/0x490 fs/erofs/decompressor.c:346
Read of size 4096 at addr ffff0000c9c29000 by task syz.4.473/7152

CPU: 1 PID: 7152 Comm: syz.4.473 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+0x1510/0x1694 fs/erofs/zdata.c:-1
 z_erofs_read_folio+0x2d8/0x5c8 fs/erofs/zdata.c:1687
 filemap_read_folio+0x134/0x384 mm/filemap.c:2490
 filemap_fault+0x98c/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+0x1cac/0x2fb0 mm/memory.c:5292
 __do_page_fault arch/arm64/mm/fault.c:499 [inline]
 do_page_fault+0x310/0x98c arch/arm64/mm/fault.c:583
 do_translation_fault+0x94/0xc8 arch/arm64/mm/fault.c:667
 do_mem_abort+0x70/0x194 arch/arm64/mm/fault.c:804
 el0_da+0x70/0x144 arch/arm64/kernel/entry-common.c:515
 el0t_64_sync_handler+0x90/0xf0 arch/arm64/kernel/entry-common.c:658
 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+0x22c/0x308 mm/slub.c:3383
 kmem_cache_zalloc include/linux/slab.h:689 [inline]
 __kernfs_new_node+0xec/0x5f4 fs/kernfs/dir.c:614
 kernfs_new_node+0x11c/0x22c fs/kernfs/dir.c:690
 __kernfs_create_file+0x60/0x2d4 fs/kernfs/file.c:1068
 sysfs_add_file_mode_ns+0x1d8/0x294 fs/sysfs/file.c:294
 create_files fs/sysfs/group.c:64 [inline]
 internal_create_group+0x3e0/0xad0 fs/sysfs/group.c:148
 sysfs_create_group+0x2c/0x3c fs/sysfs/group.c:174
 sysfs_slab_add+0x160/0x298 mm/slub.c:5981
 __kmem_cache_create+0x628/0x72c mm/slub.c:4941
 create_cache mm/slab_common.c:229 [inline]
 kmem_cache_create_usercopy+0x184/0x2fc mm/slab_common.c:335
 kmem_cache_create+0x1c/0x28 mm/slab_common.c:390
 init_se_kmem_caches+0xe0/0x2c8 drivers/target/target_core_transport.c:93
 target_core_init_configfs+0x5c/0x4f8 drivers/target/target_core_configfs.c:3600
 do_one_initcall+0x278/0x9e0 init/main.c:1310
 do_initcall_level+0x154/0x214 init/main.c:1383
 do_initcalls+0x58/0xac init/main.c:1399
 do_basic_setup+0x8c/0xa0 init/main.c:1418
 kernel_init_freeable+0x35c/0x4f0 init/main.c:1638
 kernel_init+0x24/0x1d8 init/main.c:1526
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850

The buggy address belongs to the object at ffff0000c9c29000
 which belongs to the cache kernfs_node_cache of size 168
The buggy address is located 0 bytes inside of
 168-byte region [ffff0000c9c29000, ffff0000c9c290a8)

The buggy address belongs to the physical page:
page:00000000109f0229 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x109c29
flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000200 0000000000000000 dead000000000122 ffff0000c03dca80
raw: 0000000000000000 0000000000110011 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000c9c28f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000c9c29000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000c9c29080: 00 00 00 00 00 fc fc fc fc fc fc fc fc 00 00 00
                                  ^
 ffff0000c9c29100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000c9c29180: 00 00 fc fc fc fc fc fc fc fc 00 00 00 00 00 00
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