==================================================================
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 ffff0000f662e000 by task syz.3.55/4586

CPU: 1 PID: 4586 Comm: syz.3.55 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026
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:1603
 z_erofs_read_folio+0x2dc/0x5cc fs/erofs/zdata.c:1693
 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+0x1290/0x20dc mm/filemap.c:2759
 generic_file_read_iter+0xf8/0x5ac mm/filemap.c:2941
 call_read_iter include/linux/fs.h:2259 [inline]
 new_sync_read fs/read_write.c:389 [inline]
 vfs_read+0x3cc/0x7b8 fs/read_write.c:470
 ksys_read+0x12c/0x228 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+0x98/0x290 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+0x58/0x128 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

Allocated by task 24:
 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
 kmem_cache_zalloc include/linux/slab.h:689 [inline]
 node_alloc net/ipv6/ip6_fib.c:187 [inline]
 fib6_add_1+0x94c/0x126c net/ipv6/ip6_fib.c:883
 fib6_add+0x180/0x34e8 net/ipv6/ip6_fib.c:1405
 __ip6_ins_rt net/ipv6/route.c:1349 [inline]
 ip6_ins_rt+0xc4/0x12c net/ipv6/route.c:1359
 __ipv6_ifa_notify+0x448/0xc40 net/ipv6/addrconf.c:6214
 ipv6_ifa_notify net/ipv6/addrconf.c:6253 [inline]
 addrconf_dad_completed+0x168/0xb3c net/ipv6/addrconf.c:4257
 addrconf_dad_work+0x904/0x10a0 net/ipv6/addrconf.c:-1
 process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292
 worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439
 kthread+0x254/0x2e0 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850

The buggy address belongs to the object at ffff0000f662e000
 which belongs to the cache fib6_nodes of size 72
The buggy address is located 0 bytes inside of
 72-byte region [ffff0000f662e000, ffff0000f662e048)

The buggy address belongs to the physical page:
page:00000000fcd074e5 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13662e
memcg:ffff0000dbedd401
flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000200 0000000000000000 dead000000000122 ffff0000d474c480
raw: 0000000000000000 0000000000200020 00000001ffffffff ffff0000dbedd401
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000f662df00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000f662df80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000f662e000: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
                                              ^
 ffff0000f662e080: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
 ffff0000f662e100: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
==================================================================
syz.3.55: attempt to access beyond end of device
loop3: rw=0, sector=1056, nr_sectors = 8 limit=16