syz.3.261: attempt to access beyond end of device
loop3: rw=524288, sector=8, nr_sectors = 80 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+0x39c/0x494 fs/erofs/decompressor.c:347
Read of size 4096 at addr ffff0000d95c2000 by task syz.3.261/5225

CPU: 0 PID: 5225 Comm: syz.3.261 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+0x1540/0x16a8 fs/erofs/zdata.c:-1
 z_erofs_read_folio+0x2dc/0x5cc fs/erofs/zdata.c:1693
 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
 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 4374:
 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]
 kmem_cache_alloc_node+0x258/0x344 mm/slub.c:3404
 __alloc_skb+0x128/0x728 net/core/skbuff.c:505
 alloc_skb include/linux/skbuff.h:1303 [inline]
 nlmsg_new include/net/netlink.h:998 [inline]
 __neigh_notify+0x150/0x300 net/core/neighbour.c:3522
 neigh_cleanup_and_release+0x104/0x3b4 net/core/neighbour.c:102
 neigh_del net/core/neighbour.c:226 [inline]
 neigh_remove_one+0x31c/0x424 net/core/neighbour.c:247
 neigh_forced_gc net/core/neighbour.c:280 [inline]
 neigh_alloc net/core/neighbour.c:486 [inline]
 ___neigh_create+0x474/0x24ec net/core/neighbour.c:649
 __neigh_create+0x44/0x58 net/core/neighbour.c:738
 ip6_finish_output2+0x1690/0x1864 net/ipv6/ip6_output.c:129
 __ip6_finish_output net/ipv6/ip6_output.c:205 [inline]
 ip6_finish_output+0x598/0x930 net/ipv6/ip6_output.c:216
 NF_HOOK_COND include/linux/netfilter.h:291 [inline]
 ip6_output+0x274/0x500 net/ipv6/ip6_output.c:237
 dst_output include/net/dst.h:453 [inline]
 NF_HOOK include/linux/netfilter.h:302 [inline]
 ndisc_send_skb+0xc14/0x1670 net/ipv6/ndisc.c:513
 ndisc_send_rs+0x37c/0x524 net/ipv6/ndisc.c:723
 addrconf_dad_completed+0x650/0xb3c net/ipv6/addrconf.c:4303
 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

Freed by task 4374:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4c/0x80 mm/kasan/common.c:53
 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:516
 ____kasan_slab_free+0x148/0x1b0 mm/kasan/common.c:237
 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:245
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1729 [inline]
 slab_free_freelist_hook+0x16c/0x1e8 mm/slub.c:1755
 slab_free mm/slub.c:3687 [inline]
 kmem_cache_free+0x118/0x318 mm/slub.c:3709
 kfree_skbmem+0x10c/0x198 net/core/skbuff.c:-1
 __kfree_skb net/core/skbuff.c:871 [inline]
 consume_skb+0xa8/0x104 net/core/skbuff.c:1035
 netlink_broadcast+0xf00/0x1054 net/netlink/af_netlink.c:1526
 nlmsg_multicast include/net/netlink.h:1078 [inline]
 nlmsg_notify+0xf0/0x1d4 net/netlink/af_netlink.c:2559
 rtnl_notify+0xa0/0xd8 net/core/rtnetlink.c:799
 __neigh_notify+0x1a4/0x300 net/core/neighbour.c:3533
 neigh_cleanup_and_release+0x104/0x3b4 net/core/neighbour.c:102
 neigh_del net/core/neighbour.c:226 [inline]
 neigh_remove_one+0x31c/0x424 net/core/neighbour.c:247
 neigh_forced_gc net/core/neighbour.c:280 [inline]
 neigh_alloc net/core/neighbour.c:486 [inline]
 ___neigh_create+0x474/0x24ec net/core/neighbour.c:649
 __neigh_create+0x44/0x58 net/core/neighbour.c:738
 ip6_finish_output2+0x1690/0x1864 net/ipv6/ip6_output.c:129
 __ip6_finish_output net/ipv6/ip6_output.c:205 [inline]
 ip6_finish_output+0x598/0x930 net/ipv6/ip6_output.c:216
 NF_HOOK_COND include/linux/netfilter.h:291 [inline]
 ip6_output+0x274/0x500 net/ipv6/ip6_output.c:237
 dst_output include/net/dst.h:453 [inline]
 NF_HOOK include/linux/netfilter.h:302 [inline]
 ndisc_send_skb+0xc14/0x1670 net/ipv6/ndisc.c:513
 ndisc_send_rs+0x37c/0x524 net/ipv6/ndisc.c:723
 addrconf_dad_completed+0x650/0xb3c net/ipv6/addrconf.c:4303
 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 ffff0000d95c2000
 which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 0 bytes inside of
 240-byte region [ffff0000d95c2000, ffff0000d95c20f0)

The buggy address belongs to the physical page:
page:00000000ae0299ae refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0000d95c2640 pfn:0x1195c2
flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000200 fffffc0003d29748 fffffc00032e1f48 ffff0000c0870180
raw: ffff0000d95c2640 00000000000c0006 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000d95c1f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000d95c1f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000d95c2000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff0000d95c2080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
 ffff0000d95c2100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
==================================================================