loop5: rw=524288, sector=1056, nr_sectors = 16 limit=16
syz.5.3422: attempt to access beyond end of device
loop5: rw=524288, sector=8, nr_sectors = 16 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+0x3a4/0x490 fs/erofs/decompressor.c:346
Read of size 4096 at addr ffff000108232000 by task syz.5.3422/14233

CPU: 1 PID: 14233 Comm: syz.5.3422 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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+0x152c/0x16cc fs/erofs/zdata.c:1603
 z_erofs_read_folio+0x2d8/0x5c8 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+0x12cc/0x2104 mm/filemap.c:2759
 generic_file_read_iter+0xf8/0x5c4 mm/filemap.c:2941
 call_read_iter include/linux/fs.h:2259 [inline]
 new_sync_read fs/read_write.c:389 [inline]
 vfs_read+0x3d4/0x7f0 fs/read_write.c:470
 ksys_read+0x12c/0x224 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+0x98/0x2b4 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x130 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 12224:
 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
 skb_clone+0x190/0x304 net/core/skbuff.c:1660
 deliver_clone net/bridge/br_forward.c:125 [inline]
 maybe_deliver+0xac/0x174 net/bridge/br_forward.c:190
 br_flood+0x28c/0x3f4 net/bridge/br_forward.c:232
 br_dev_xmit+0xd08/0x1320 net/bridge/br_device.c:-1
 __netdev_start_xmit include/linux/netdevice.h:4894 [inline]
 netdev_start_xmit include/linux/netdevice.h:4908 [inline]
 xmit_one net/core/dev.c:3695 [inline]
 dev_hard_start_xmit+0x234/0x8cc net/core/dev.c:3711
 __dev_queue_xmit+0x15b8/0x3118 net/core/dev.c:4375
 dev_queue_xmit include/linux/netdevice.h:3051 [inline]
 neigh_hh_output include/net/neighbour.h:529 [inline]
 neigh_output include/net/neighbour.h:543 [inline]
 ip6_finish_output2+0xd28/0x1840 net/ipv6/ip6_output.c:138
 __ip6_finish_output net/ipv6/ip6_output.c:205 [inline]
 ip6_finish_output+0x594/0x92c 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+0x15c/0x444 include/linux/netfilter.h:302
 mld_sendpack+0x88c/0x10ec net/ipv6/mcast.c:1825
 mld_send_cr net/ipv6/mcast.c:2126 [inline]
 mld_ifc_work+0x768/0xa88 net/ipv6/mcast.c:2658
 process_one_work+0x7f8/0x13a4 kernel/workqueue.c:2292
 worker_thread+0x8c4/0xfec kernel/workqueue.c:2439
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850

Freed by task 12224:
 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+0x118/0x314 mm/slub.c:3709
 kfree_skbmem+0x10c/0x198 net/core/skbuff.c:-1
 __kfree_skb net/core/skbuff.c:871 [inline]
 kfree_skb_reason+0x1a0/0x418 net/core/skbuff.c:893
 kfree_skb include/linux/skbuff.h:1252 [inline]
 ip6_mc_input+0x808/0xb14 net/ipv6/ip6_input.c:589
 dst_input include/net/dst.h:463 [inline]
 ip6_rcv_finish+0x1f4/0x220 net/ipv6/ip6_input.c:79
 NF_HOOK+0x2dc/0x36c include/linux/netfilter.h:302
 ipv6_rcv+0x9c/0xbc net/ipv6/ip6_input.c:310
 __netif_receive_skb_one_core net/core/dev.c:5619 [inline]
 __netif_receive_skb+0xcc/0x2a8 net/core/dev.c:5733
 process_backlog+0x408/0x710 net/core/dev.c:6061
 __napi_poll+0xb4/0x3f0 net/core/dev.c:6628
 napi_poll net/core/dev.c:6695 [inline]
 net_rx_action+0x514/0xb18 net/core/dev.c:6809
 handle_softirqs+0x318/0xc60 kernel/softirq.c:596
 __do_softirq+0x14/0x20 kernel/softirq.c:630

The buggy address belongs to the object at ffff000108232000
 which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 0 bytes inside of
 240-byte region [ffff000108232000, ffff0001082320f0)

The buggy address belongs to the physical page:
page:00000000bcdf8c93 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x148232
flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000200 fffffc00033ad480 dead000000000004 ffff0000c086c180
raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff000108231f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff000108231f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff000108232000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff000108232080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
 ffff000108232100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
==================================================================
syz.5.3422: attempt to access beyond end of device
loop5: rw=0, sector=1056, nr_sectors = 8 limit=16