loop0: rw=524288, sector=88, nr_sectors = 48 limit=16 syz.0.1141: attempt to access beyond end of device loop0: 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+0x3a4/0x490 fs/erofs/decompressor.c:346 Read of size 4096 at addr ffff0000f3d1f000 by task syz.0.1141/9412 CPU: 0 PID: 9412 Comm: syz.0.1141 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 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 el1_abort+0x3c/0x5c arch/arm64/kernel/entry-common.c:367 el1h_64_sync_handler+0x50/0xac arch/arm64/kernel/entry-common.c:427 el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:580 __arch_copy_from_user+0xc8/0x230 arch/arm64/lib/copy_template.S:114 do_ipv6_getsockopt+0x1ac/0x1c24 net/ipv6/ipv6_sockglue.c:1147 ipv6_getsockopt+0xc4/0x3f4 net/ipv6/ipv6_sockglue.c:1502 udpv6_getsockopt+0x94/0xac net/ipv6/udp.c:1721 sock_common_getsockopt+0xa8/0xc4 net/core/sock.c:3664 __sys_getsockopt+0x1e0/0x478 net/socket.c:2331 __do_sys_getsockopt net/socket.c:2346 [inline] __se_sys_getsockopt net/socket.c:2343 [inline] __arm64_sys_getsockopt+0xb8/0xd4 net/socket.c:2343 __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 4320: 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 kstrdup mm/util.c:61 [inline] kstrdup_const+0x90/0xdc mm/util.c:84 __kernfs_new_node+0xb0/0x5f4 fs/kernfs/dir.c:610 kernfs_new_node+0x11c/0x22c fs/kernfs/dir.c:690 kernfs_create_dir_ns+0x58/0x12c fs/kernfs/dir.c:1046 sysfs_create_dir_ns+0x120/0x264 fs/sysfs/dir.c:59 create_dir lib/kobject.c:63 [inline] kobject_add_internal+0x598/0xb08 lib/kobject.c:231 kobject_add_varg lib/kobject.c:366 [inline] kobject_add+0x140/0x20c lib/kobject.c:418 device_add+0x3f0/0xf90 drivers/base/core.c:3632 device_create_groups_vargs+0x1e8/0x280 drivers/base/core.c:4391 device_create+0xf4/0x148 drivers/base/core.c:4433 macvtap_device_event+0x29c/0x394 drivers/net/macvtap.c:177 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:2001 [inline] call_netdevice_notifiers_extack net/core/dev.c:2039 [inline] call_netdevice_notifiers+0x110/0x198 net/core/dev.c:2053 register_netdevice+0x119c/0x15dc net/core/dev.c:10237 macvlan_common_newlink+0xd04/0x1254 drivers/net/macvlan.c:1512 macvtap_newlink+0x15c/0x1dc drivers/net/macvtap.c:109 rtnl_newlink_create net/core/rtnetlink.c:3422 [inline] __rtnl_newlink net/core/rtnetlink.c:3642 [inline] rtnl_newlink+0x1058/0x1a50 net/core/rtnetlink.c:3655 rtnetlink_rcv_msg+0x698/0xcdc net/core/rtnetlink.c:6150 netlink_rcv_skb+0x218/0x3e8 net/netlink/af_netlink.c:2511 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6168 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x60c/0x814 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x6f4/0x9c0 net/netlink/af_netlink.c:1872 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] __sys_sendto+0x324/0x440 net/socket.c:2152 __do_sys_sendto net/socket.c:2164 [inline] __se_sys_sendto net/socket.c:2160 [inline] __arm64_sys_sendto+0xd8/0xf8 net/socket.c:2160 __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 The buggy address belongs to the object at ffff0000f3d1f000 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 0 bytes inside of 128-byte region [ffff0000f3d1f000, ffff0000f3d1f080) The buggy address belongs to the physical page: page:0000000015a1d00f refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0000f3d1ff00 pfn:0x133d1f flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000200 fffffc0003d2e348 fffffc0003d44b08 ffff0000c0002300 raw: ffff0000f3d1ff00 000000000010000b 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000f3d1ef00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000f3d1ef80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000f3d1f000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000f3d1f080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0000f3d1f100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================