TC_ACT_REPEAT abuse ? ===================================================== BUG: KMSAN: uninit-value in __skb_flow_dissect+0x2013/0xa060 net/core/flow_dissector.c:1198 __skb_flow_dissect+0x2013/0xa060 net/core/flow_dissector.c:1198 skb_flow_dissect_flow_keys include/linux/skbuff.h:1614 [inline] cake_hash net/sched/sch_cake.c:730 [inline] cake_classify net/sched/sch_cake.c:1754 [inline] cake_enqueue+0x114b/0xf6c0 net/sched/sch_cake.c:1772 dev_qdisc_enqueue net/core/dev.c:4174 [inline] __dev_xmit_skb net/core/dev.c:4289 [inline] __dev_queue_xmit+0x23c3/0x5a00 net/core/dev.c:4831 dev_queue_xmit include/linux/netdevice.h:3418 [inline] packet_xmit+0x8f/0x710 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3082 [inline] packet_sendmsg+0x8c6b/0x9d60 net/packet/af_packet.c:3114 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0xf37/0xfd0 net/socket.c:2699 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2753 __sys_sendmsg net/socket.c:2785 [inline] __do_sys_sendmsg net/socket.c:2790 [inline] __se_sys_sendmsg net/socket.c:2788 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2788 x64_sys_call+0x1e20/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15d/0x3c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was stored to memory at: skb_data_move+0x3b4/0x4f0 include/linux/skbuff.h:-1 skb_postpush_data_move include/linux/skbuff.h:4680 [inline] __vlan_insert_inner_tag include/linux/if_vlan.h:375 [inline] __vlan_insert_tag include/linux/if_vlan.h:414 [inline] skb_vlan_push+0x647/0xb70 net/core/skbuff.c:6478 tcf_vlan_act+0xc09/0x12c0 net/sched/act_vlan.c:49 tc_act include/net/tc_wrapper.h:131 [inline] tcf_action_exec+0x21f/0x1190 net/sched/act_api.c:1147 tcf_exts_exec include/net/pkt_cls.h:349 [inline] mall_classify+0x183/0x290 net/sched/cls_matchall.c:42 tc_classify include/net/tc_wrapper.h:198 [inline] __tcf_classify net/sched/cls_api.c:1764 [inline] tcf_classify+0x855/0x1ca0 net/sched/cls_api.c:1860 cake_classify net/sched/sch_cake.c:1733 [inline] cake_enqueue+0x168/0xf6c0 net/sched/sch_cake.c:1772 dev_qdisc_enqueue net/core/dev.c:4174 [inline] __dev_xmit_skb net/core/dev.c:4289 [inline] __dev_queue_xmit+0x23c3/0x5a00 net/core/dev.c:4831 dev_queue_xmit include/linux/netdevice.h:3418 [inline] packet_xmit+0x8f/0x710 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3082 [inline] packet_sendmsg+0x8c6b/0x9d60 net/packet/af_packet.c:3114 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0xf37/0xfd0 net/socket.c:2699 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2753 __sys_sendmsg net/socket.c:2785 [inline] __do_sys_sendmsg net/socket.c:2790 [inline] __se_sys_sendmsg net/socket.c:2788 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2788 x64_sys_call+0x1e20/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15d/0x3c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was stored to memory at: skb_data_move+0x3b4/0x4f0 include/linux/skbuff.h:-1 skb_postpush_data_move include/linux/skbuff.h:4680 [inline] __vlan_insert_inner_tag include/linux/if_vlan.h:375 [inline] __vlan_insert_tag include/linux/if_vlan.h:414 [inline] skb_vlan_push+0x647/0xb70 net/core/skbuff.c:6478 tcf_vlan_act+0xc09/0x12c0 net/sched/act_vlan.c:49 tc_act include/net/tc_wrapper.h:131 [inline] tcf_action_exec+0x21f/0x1190 net/sched/act_api.c:1147 tcf_exts_exec include/net/pkt_cls.h:349 [inline] mall_classify+0x183/0x290 net/sched/cls_matchall.c:42 tc_classify include/net/tc_wrapper.h:198 [inline] __tcf_classify net/sched/cls_api.c:1764 [inline] tcf_classify+0x855/0x1ca0 net/sched/cls_api.c:1860 cake_classify net/sched/sch_cake.c:1733 [inline] cake_enqueue+0x168/0xf6c0 net/sched/sch_cake.c:1772 dev_qdisc_enqueue net/core/dev.c:4174 [inline] __dev_xmit_skb net/core/dev.c:4289 [inline] __dev_queue_xmit+0x23c3/0x5a00 net/core/dev.c:4831 dev_queue_xmit include/linux/netdevice.h:3418 [inline] packet_xmit+0x8f/0x710 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3082 [inline] packet_sendmsg+0x8c6b/0x9d60 net/packet/af_packet.c:3114 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0xf37/0xfd0 net/socket.c:2699 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2753 __sys_sendmsg net/socket.c:2785 [inline] __do_sys_sendmsg net/socket.c:2790 [inline] __se_sys_sendmsg net/socket.c:2788 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2788 x64_sys_call+0x1e20/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15d/0x3c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was stored to memory at: pskb_expand_head+0x497/0x1a40 net/core/skbuff.c:2311 __skb_cow include/linux/skbuff.h:3881 [inline] skb_cow_head include/linux/skbuff.h:3915 [inline] __vlan_insert_inner_tag include/linux/if_vlan.h:368 [inline] __vlan_insert_tag include/linux/if_vlan.h:414 [inline] skb_vlan_push+0x444/0xb70 net/core/skbuff.c:6478 tcf_vlan_act+0xc09/0x12c0 net/sched/act_vlan.c:49 tc_act include/net/tc_wrapper.h:131 [inline] tcf_action_exec+0x21f/0x1190 net/sched/act_api.c:1147 tcf_exts_exec include/net/pkt_cls.h:349 [inline] mall_classify+0x183/0x290 net/sched/cls_matchall.c:42 tc_classify include/net/tc_wrapper.h:198 [inline] __tcf_classify net/sched/cls_api.c:1764 [inline] tcf_classify+0x855/0x1ca0 net/sched/cls_api.c:1860 cake_classify net/sched/sch_cake.c:1733 [inline] cake_enqueue+0x168/0xf6c0 net/sched/sch_cake.c:1772 dev_qdisc_enqueue net/core/dev.c:4174 [inline] __dev_xmit_skb net/core/dev.c:4289 [inline] __dev_queue_xmit+0x23c3/0x5a00 net/core/dev.c:4831 dev_queue_xmit include/linux/netdevice.h:3418 [inline] packet_xmit+0x8f/0x710 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3082 [inline] packet_sendmsg+0x8c6b/0x9d60 net/packet/af_packet.c:3114 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0xf37/0xfd0 net/socket.c:2699 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2753 __sys_sendmsg net/socket.c:2785 [inline] __do_sys_sendmsg net/socket.c:2790 [inline] __se_sys_sendmsg net/socket.c:2788 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2788 x64_sys_call+0x1e20/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15d/0x3c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was stored to memory at: skb_data_move+0x3b4/0x4f0 include/linux/skbuff.h:-1 skb_postpush_data_move include/linux/skbuff.h:4680 [inline] __vlan_insert_inner_tag include/linux/if_vlan.h:375 [inline] __vlan_insert_tag include/linux/if_vlan.h:414 [inline] skb_vlan_push+0x647/0xb70 net/core/skbuff.c:6478 tcf_vlan_act+0xc09/0x12c0 net/sched/act_vlan.c:49 tc_act include/net/tc_wrapper.h:131 [inline] tcf_action_exec+0x21f/0x1190 net/sched/act_api.c:1147 tcf_exts_exec include/net/pkt_cls.h:349 [inline] mall_classify+0x183/0x290 net/sched/cls_matchall.c:42 tc_classify include/net/tc_wrapper.h:198 [inline] __tcf_classify net/sched/cls_api.c:1764 [inline] tcf_classify+0x855/0x1ca0 net/sched/cls_api.c:1860 cake_classify net/sched/sch_cake.c:1733 [inline] cake_enqueue+0x168/0xf6c0 net/sched/sch_cake.c:1772 dev_qdisc_enqueue net/core/dev.c:4174 [inline] __dev_xmit_skb net/core/dev.c:4289 [inline] __dev_queue_xmit+0x23c3/0x5a00 net/core/dev.c:4831 dev_queue_xmit include/linux/netdevice.h:3418 [inline] packet_xmit+0x8f/0x710 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3082 [inline] packet_sendmsg+0x8c6b/0x9d60 net/packet/af_packet.c:3114 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0xf37/0xfd0 net/socket.c:2699 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2753 __sys_sendmsg net/socket.c:2785 [inline] __do_sys_sendmsg net/socket.c:2790 [inline] __se_sys_sendmsg net/socket.c:2788 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2788 x64_sys_call+0x1e20/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15d/0x3c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was stored to memory at: skb_data_move+0x3b4/0x4f0 include/linux/skbuff.h:-1 skb_postpush_data_move include/linux/skbuff.h:4680 [inline] __vlan_insert_inner_tag include/linux/if_vlan.h:375 [inline] __vlan_insert_tag include/linux/if_vlan.h:414 [inline] skb_vlan_push+0x647/0xb70 net/core/skbuff.c:6478 tcf_vlan_act+0xc09/0x12c0 net/sched/act_vlan.c:49 tc_act include/net/tc_wrapper.h:131 [inline] tcf_action_exec+0x21f/0x1190 net/sched/act_api.c:1147 tcf_exts_exec include/net/pkt_cls.h:349 [inline] mall_classify+0x183/0x290 net/sched/cls_matchall.c:42 tc_classify include/net/tc_wrapper.h:198 [inline] __tcf_classify net/sched/cls_api.c:1764 [inline] tcf_classify+0x855/0x1ca0 net/sched/cls_api.c:1860 cake_classify net/sched/sch_cake.c:1733 [inline] cake_enqueue+0x168/0xf6c0 net/sched/sch_cake.c:1772 dev_qdisc_enqueue net/core/dev.c:4174 [inline] __dev_xmit_skb net/core/dev.c:4289 [inline] __dev_queue_xmit+0x23c3/0x5a00 net/core/dev.c:4831 dev_queue_xmit include/linux/netdevice.h:3418 [inline] packet_xmit+0x8f/0x710 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3082 [inline] packet_sendmsg+0x8c6b/0x9d60 net/packet/af_packet.c:3114 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0xf37/0xfd0 net/socket.c:2699 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2753 __sys_sendmsg net/socket.c:2785 [inline] __do_sys_sendmsg net/socket.c:2790 [inline] __se_sys_sendmsg net/socket.c:2788 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2788 x64_sys_call+0x1e20/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15d/0x3c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was stored to memory at: skb_data_move+0x3b4/0x4f0 include/linux/skbuff.h:-1 skb_postpush_data_move include/linux/skbuff.h:4680 [inline] __vlan_insert_inner_tag include/linux/if_vlan.h:375 [inline] __vlan_insert_tag include/linux/if_vlan.h:414 [inline] skb_vlan_push+0x647/0xb70 net/core/skbuff.c:6478 tcf_vlan_act+0xc09/0x12c0 net/sched/act_vlan.c:49 tc_act include/net/tc_wrapper.h:131 [inline] tcf_action_exec+0x21f/0x1190 net/sched/act_api.c:1147 tcf_exts_exec include/net/pkt_cls.h:349 [inline] mall_classify+0x183/0x290 net/sched/cls_matchall.c:42 tc_classify include/net/tc_wrapper.h:198 [inline] __tcf_classify net/sched/cls_api.c:1764 [inline] tcf_classify+0x855/0x1ca0 net/sched/cls_api.c:1860 cake_classify net/sched/sch_cake.c:1733 [inline] cake_enqueue+0x168/0xf6c0 net/sched/sch_cake.c:1772 dev_qdisc_enqueue net/core/dev.c:4174 [inline] __dev_xmit_skb net/core/dev.c:4289 [inline] __dev_queue_xmit+0x23c3/0x5a00 net/core/dev.c:4831 dev_queue_xmit include/linux/netdevice.h:3418 [inline] packet_xmit+0x8f/0x710 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3082 [inline] packet_sendmsg+0x8c6b/0x9d60 net/packet/af_packet.c:3114 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0xf37/0xfd0 net/socket.c:2699 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2753 __sys_sendmsg net/socket.c:2785 [inline] __do_sys_sendmsg net/socket.c:2790 [inline] __se_sys_sendmsg net/socket.c:2788 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2788 x64_sys_call+0x1e20/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15d/0x3c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was stored to memory at: skb_data_move+0x3b4/0x4f0 include/linux/skbuff.h:-1 skb_postpush_data_move include/linux/skbuff.h:4680 [inline] __vlan_insert_inner_tag include/linux/if_vlan.h:375 [inline] __vlan_insert_tag include/linux/if_vlan.h:414 [inline] skb_vlan_push+0x647/0xb70 net/core/skbuff.c:6478 tcf_vlan_act+0xc09/0x12c0 net/sched/act_vlan.c:49 tc_act include/net/tc_wrapper.h:131 [inline] tcf_action_exec+0x21f/0x1190 net/sched/act_api.c:1147 tcf_exts_exec include/net/pkt_cls.h:349 [inline] mall_classify+0x183/0x290 net/sched/cls_matchall.c:42 tc_classify include/net/tc_wrapper.h:198 [inline] __tcf_classify net/sched/cls_api.c:1764 [inline] tcf_classify+0x855/0x1ca0 net/sched/cls_api.c:1860 cake_classify net/sched/sch_cake.c:1733 [inline] cake_enqueue+0x168/0xf6c0 net/sched/sch_cake.c:1772 dev_qdisc_enqueue net/core/dev.c:4174 [inline] __dev_xmit_skb net/core/dev.c:4289 [inline] __dev_queue_xmit+0x23c3/0x5a00 net/core/dev.c:4831 dev_queue_xmit include/linux/netdevice.h:3418 [inline] packet_xmit+0x8f/0x710 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3082 [inline] packet_sendmsg+0x8c6b/0x9d60 net/packet/af_packet.c:3114 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0xf37/0xfd0 net/socket.c:2699 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2753 __sys_sendmsg net/socket.c:2785 [inline] __do_sys_sendmsg net/socket.c:2790 [inline] __se_sys_sendmsg net/socket.c:2788 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2788 x64_sys_call+0x1e20/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15d/0x3c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was created at: slab_post_alloc_hook mm/slub.c:4577 [inline] slab_alloc_node mm/slub.c:4899 [inline] kmem_cache_alloc_node_noprof+0x3cd/0x12c0 mm/slub.c:4951 kmalloc_reserve net/core/skbuff.c:613 [inline] __alloc_skb+0x855/0x1190 net/core/skbuff.c:713 alloc_skb include/linux/skbuff.h:1385 [inline] alloc_skb_with_frags+0xc5/0x990 net/core/skbuff.c:6766 sock_alloc_send_pskb+0xacb/0xc60 net/core/sock.c:3007 packet_alloc_skb net/packet/af_packet.c:2932 [inline] packet_snd net/packet/af_packet.c:3025 [inline] packet_sendmsg+0x6ed5/0x9d60 net/packet/af_packet.c:3114 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0xf37/0xfd0 net/socket.c:2699 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2753 __sys_sendmsg net/socket.c:2785 [inline] __do_sys_sendmsg net/socket.c:2790 [inline] __se_sys_sendmsg net/socket.c:2788 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2788 x64_sys_call+0x1e20/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15d/0x3c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f CPU: 0 UID: 0 PID: 10647 Comm: syz.8.929 Tainted: G L syzkaller #0 PREEMPT(lazy) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 =====================================================