loop4: rw=524288, sector=24, nr_sectors = 112 limit=16
syz.4.70: attempt to access beyond end of device
loop4: rw=524288, sector=16, nr_sectors = 8 limit=16
==================================================================
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 ffff0000f66c9000 by task syz.4.70/4740

CPU: 1 PID: 4740 Comm: syz.4.70 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026
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+0x14d4/0x1694 fs/erofs/zdata.c:1597
 z_erofs_read_folio+0x2d8/0x5c8 fs/erofs/zdata.c:1687
 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 4333:
 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_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0xa0/0xb8 mm/kasan/common.c:384
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 kmalloc_trace+0x7c/0x94 mm/slab_common.c:1031
 kmalloc include/linux/slab.h:563 [inline]
 kzalloc include/linux/slab.h:699 [inline]
 ref_tracker_alloc+0x138/0x3f0 lib/ref_tracker.c:85
 __netdev_tracker_alloc include/linux/netdevice.h:4051 [inline]
 netdev_hold include/linux/netdevice.h:4080 [inline]
 dst_init+0xc8/0x3c0 net/core/dst.c:52
 dst_alloc+0x120/0x170 net/core/dst.c:92
 ip6_dst_alloc net/ipv6/route.c:345 [inline]
 icmp6_dst_alloc+0x80/0x404 net/ipv6/route.c:3308
 mld_sendpack+0x790/0x10ec net/ipv6/mcast.c:1814
 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

The buggy address belongs to the object at ffff0000f66c9000
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 0 bytes inside of
 128-byte region [ffff0000f66c9000, ffff0000f66c9080)

The buggy address belongs to the physical page:
page:00000000b1ae71b5 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1366c9
flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000200 fffffc00033f1b00 dead000000000003 ffff0000c0002300
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000f66c8f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000f66c8f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000f66c9000: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
                               ^
 ffff0000f66c9080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000f66c9100: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
syz.4.70: attempt to access beyond end of device
loop4: rw=0, sector=1056, nr_sectors = 8 limit=16