netlink: 4 bytes leftover after parsing attributes in process `syz-executor.2'. ===================================================== BUG: KMSAN: uninit-value in nla_ok include/net/netlink.h:1094 [inline] BUG: KMSAN: uninit-value in __nla_validate_parse+0x422/0x3450 lib/nlattr.c:369 CPU: 1 PID: 28976 Comm: syz-executor.2 Not tainted 5.7.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x220 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 nla_ok include/net/netlink.h:1094 [inline] __nla_validate_parse+0x422/0x3450 lib/nlattr.c:369 __nla_parse+0x137/0x150 lib/nlattr.c:478 nla_parse_nested include/net/netlink.h:1147 [inline] fl_set_erspan_opt+0x30e/0xd40 net/sched/cls_flower.c:1040 fl_set_enc_opt net/sched/cls_flower.c:1198 [inline] fl_set_key+0x6322/0x8e10 net/sched/cls_flower.c:1471 fl_set_parms net/sched/cls_flower.c:1707 [inline] fl_change+0x1202/0x7530 net/sched/cls_flower.c:1806 tc_new_tfilter+0x31a8/0x4f40 net/sched/cls_api.c:2168 rtnetlink_rcv_msg+0xcb7/0x1570 net/core/rtnetlink.c:5445 netlink_rcv_skb+0x451/0x650 net/netlink/af_netlink.c:2469 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:5472 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0xf9e/0x1100 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x1246/0x14d0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x12b6/0x1350 net/socket.c:2362 ___sys_sendmsg net/socket.c:2416 [inline] __sys_sendmmsg+0x5fe/0xd60 net/socket.c:2506 __do_sys_sendmmsg net/socket.c:2535 [inline] __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2532 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2532 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45ca59 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f1dee04dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00000000004fd380 RCX: 000000000045ca59 RDX: 010efe10675dec16 RSI: 0000000020000200 RDI: 0000000000000003 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000900 R14: 00000000004cbcfa R15: 00007f1dee04e6d4 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80 slab_alloc_node mm/slub.c:2802 [inline] __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4436 __kmalloc_reserve net/core/skbuff.c:142 [inline] __alloc_skb+0x2fd/0xac0 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1083 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1175 [inline] netlink_sendmsg+0x7d3/0x14d0 net/netlink/af_netlink.c:1893 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x12b6/0x1350 net/socket.c:2362 ___sys_sendmsg net/socket.c:2416 [inline] __sys_sendmmsg+0x5fe/0xd60 net/socket.c:2506 __do_sys_sendmmsg net/socket.c:2535 [inline] __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2532 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2532 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x44/0xa9 =====================================================