netlink: 44 bytes leftover after parsing attributes in process `syz.0.17'. ------------[ cut here ]------------ memcpy: detected field-spanning write (size 32) of single field "&new->sel" at net/sched/cls_u32.c:854 (size 16) WARNING: CPU: 1 PID: 4453 at net/sched/cls_u32.c:854 u32_init_knode net/sched/cls_u32.c:854 [inline] WARNING: CPU: 1 PID: 4453 at net/sched/cls_u32.c:854 u32_change+0x1698/0x1f18 net/sched/cls_u32.c:920 Modules linked in: CPU: 1 PID: 4453 Comm: syz.0.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 pstate: 62400005 (nZCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) pc : u32_init_knode net/sched/cls_u32.c:854 [inline] pc : u32_change+0x1698/0x1f18 net/sched/cls_u32.c:920 lr : u32_init_knode net/sched/cls_u32.c:854 [inline] lr : u32_change+0x1698/0x1f18 net/sched/cls_u32.c:920 sp : ffff800021436be0 x29: ffff800021436d40 x28: ffff0000c2eff600 x27: 0000000000000000 x26: 1fffe000185dfecd x25: ffff0000cb6dc800 x24: ffff0000cb6a6000 x23: 0000000000000010 x22: ffff700004286d8c x21: dfff800000000000 x20: ffff800021437400 x19: ffff800017bd9000 x18: 0000000000000000 x17: 20646c6569662065 x16: ffff8000082d9364 x15: 0000000000000000 x14: 0000000000000001 x13: 1fffe00033eac9a3 x12: 0000000000ff0100 x11: ff00800008194238 x10: 0000000000000000 x9 : c3210f00bd4d3500 x8 : c3210f00bd4d3500 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff800021436678 x4 : ffff8000152f4cc0 x3 : ffff800008538704 x2 : 0000000000000001 x1 : 0000000100000000 x0 : 0000000000000000 Call trace: u32_init_knode net/sched/cls_u32.c:854 [inline] u32_change+0x1698/0x1f18 net/sched/cls_u32.c:920 tc_new_tfilter+0xc28/0x1370 net/sched/cls_api.c:2187 rtnetlink_rcv_msg+0x6d8/0xcdc net/core/rtnetlink.c:6141 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_sendmsg+0x5c8/0x938 net/socket.c:2518 ___sys_sendmsg net/socket.c:2572 [inline] __sys_sendmmsg+0x344/0x834 net/socket.c:2658 __do_sys_sendmmsg net/socket.c:2687 [inline] __se_sys_sendmmsg net/socket.c:2684 [inline] __arm64_sys_sendmmsg+0xa0/0xbc net/socket.c:2684 __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 irq event stamp: 2046 hardirqs last enabled at (2045): [] __up_console_sem+0xb4/0xfc kernel/printk/printk.c:261 hardirqs last disabled at (2046): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405 softirqs last enabled at (2010): [] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32 softirqs last disabled at (2002): [] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19 ---[ end trace 0000000000000000 ]--- Zero length message leads to an empty skb