syz.5.1903: attempt to access beyond end of device loop5: rw=524288, sector=8, nr_sectors = 80 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 ffff0000f3010000 by task syz.5.1903/10655 CPU: 0 PID: 10655 Comm: syz.5.1903 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+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 3989: 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] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc_node_track_caller+0xe0/0x16c mm/slab_common.c:956 kmemdup+0x5c/0x98 mm/util.c:129 kmemdup include/linux/fortify-string.h:585 [inline] neigh_sysctl_register+0xc0/0x8e0 net/core/neighbour.c:3796 devinet_sysctl_register+0xb0/0x1c0 net/ipv4/devinet.c:2649 inetdev_init+0x268/0x4a0 net/ipv4/devinet.c:280 inetdev_event+0xf04/0x12d8 net/ipv4/devinet.c:1547 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:455 call_netdevice_notifiers_info net/core/dev.c:2014 [inline] call_netdevice_notifiers_extack net/core/dev.c:2052 [inline] call_netdevice_notifiers+0x110/0x198 net/core/dev.c:2066 register_netdevice+0x11a8/0x160c net/core/dev.c:10263 lapbeth_new_device drivers/net/wan/lapbether.c:418 [inline] lapbeth_device_event+0x690/0x950 drivers/net/wan/lapbether.c:460 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:455 call_netdevice_notifiers_info net/core/dev.c:2014 [inline] call_netdevice_notifiers_extack net/core/dev.c:2052 [inline] call_netdevice_notifiers net/core/dev.c:2066 [inline] __dev_notify_flags+0x250/0x480 net/core/dev.c:8702 dev_change_flags+0xc8/0x154 net/core/dev.c:8740 devinet_ioctl+0x88c/0x17dc net/ipv4/devinet.c:1156 inet_ioctl+0x328/0x51c net/ipv4/af_inet.c:1008 sock_do_ioctl+0x100/0x258 net/socket.c:1201 sock_ioctl+0x238/0x824 net/socket.c:1320 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856 __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 Last potentially related work creation: kasan_save_stack+0x40/0x70 mm/kasan/common.c:46 __kasan_record_aux_stack+0xc0/0xdc mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:496 call_rcu+0x100/0x94c kernel/rcu/tree.c:2849 in6_dev_finish_destroy+0x158/0x1d4 net/ipv6/addrconf_core.c:278 in6_dev_put include/net/addrconf.h:388 [inline] addrconf_ifdown+0x1368/0x15ec net/ipv6/addrconf.c:3954 addrconf_notify+0x340/0xc8c net/ipv6/addrconf.c:-1 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:455 call_netdevice_notifiers_info net/core/dev.c:2014 [inline] call_netdevice_notifiers_extack net/core/dev.c:2052 [inline] call_netdevice_notifiers net/core/dev.c:2066 [inline] unregister_netdevice_many+0xe6c/0x177c net/core/dev.c:11016 unregister_netdevice_queue+0x2b0/0x304 net/core/dev.c:10947 unregister_netdevice include/linux/netdevice.h:3075 [inline] __tun_detach+0xb04/0x1224 drivers/net/tun.c:685 tun_detach drivers/net/tun.c:701 [inline] tun_chr_close+0x118/0x1f4 drivers/net/tun.c:3492 __fput+0x1bc/0x7b8 fs/file_table.c:320 ____fput+0x20/0x30 fs/file_table.c:348 task_work_run+0x1ec/0x278 kernel/task_work.c:203 get_signal+0x111c/0x1304 kernel/signal.c:2648 do_signal arch/arm64/kernel/signal.c:1095 [inline] do_notify_resume+0x33c/0x2aa4 arch/arm64/kernel/signal.c:1148 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 The buggy address belongs to the object at ffff0000f3010000 which belongs to the cache kmalloc-cg-2k of size 2048 The buggy address is located 0 bytes inside of 2048-byte region [ffff0000f3010000, ffff0000f3010800) The buggy address belongs to the physical page: page:0000000089c55228 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0000f3017000 pfn:0x133010 head:0000000089c55228 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff0000c0036401 flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000010200 fffffc0003cc1208 fffffc0003670808 ffff0000c0003380 raw: ffff0000f3017000 0000000000080007 00000001ffffffff ffff0000c0036401 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000f3010480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000f3010500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000f3010580: 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff0000f3010600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0000f3010680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================