{"id":"CVE-2026-98934","summary":"ipv6: sr: use skb_get_hash_net() in seg6_make_flowlabel()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: sr: use skb_get_hash_net() in seg6_make_flowlabel()\n\nSince commit d58e468b1112 (\"flow_dissector: implements flow dissector\nBPF hook\") __skb_flow_dissect() needs a net pointer, either from\nskb-\u003edev, skb-\u003esk, or since commit 3cbf4ffba5ee (\"net: plumb network\nnamespace into __skb_flow_dissect\") a caller provided pointer.\n\nsyzbot was able to reach seg6_make_flowlabel() with an skb having\nneither skb-\u003edev nor skb-\u003esk set: a TIPC UDP bearer sends a discovery\nmessage through an IPv4 route using seg6 encap, while\nnet.ipv6.seg6_flowlabel is set to 1.\n\nseg6_make_flowlabel() already has a net pointer, use skb_get_hash_net().\n\nWARNING: net/core/flow_dissector.c:1131 at __skb_flow_dissect+0x910/0x5368 net/core/flow_dissector.c:1126, CPU#0: syz.0.17/4930\nCall trace:\n  __skb_flow_dissect+0x910/0x5368 net/core/flow_dissector.c:1126 (P)\n  __skb_get_hash_net+0xe0/0x29c net/core/flow_dissector.c:1903\n  skb_get_hash include/linux/skbuff.h:1663 [inline]\n  seg6_make_flowlabel+0xcc/0x1ec net/ipv6/seg6_iptunnel.c:132\n  __seg6_do_srh_encap+0x320/0xbf4 net/ipv6/seg6_iptunnel.c:161\n  seg6_do_srh+0x4b4/0xa44 net/ipv6/seg6_iptunnel.c:431\n  seg6_output_core+0x164/0x688 net/ipv6/seg6_iptunnel.c:681\n  seg6_output+0x44/0x1ac net/ipv6/seg6_iptunnel.c:744\n  lwtunnel_output+0x3d0/0x664 net/core/lwtunnel.c:356\n  dst_output include/net/dst.h:470 [inline]\n  ip_local_out+0x110/0x148 net/ipv4/ip_output.c:131\n  iptunnel_xmit+0x50c/0xd38 net/ipv4/ip_tunnel_core.c:97\n  udp_tunnel_xmit_skb+0x220/0x348 net/ipv4/udp_tunnel_core.c:187\n  tipc_udp_xmit+0x75c/0x9c0 net/tipc/udp_media.c:202\n  tipc_udp_send_msg+0x214/0x374 net/tipc/udp_media.c:274\n  tipc_bearer_xmit_skb+0x260/0x3b0 net/tipc/bearer.c:576\n  tipc_enable_bearer net/tipc/bearer.c:366 [inline]\n  __tipc_nl_bearer_enable+0xc90/0xfb0 net/tipc/bearer.c:1048\n  tipc_nl_bearer_enable+0x2c/0x48 net/tipc/bearer.c:1057\n  genl_family_rcv_msg_doit+0x1e4/0x2d4 net/netlink/genetlink.c:1114","modified":"2026-11-01T02:34:10.536886951Z","published":"2026-10-23T12:11:43.459Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98934.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/086e8acb3a0e55f6d22d29fae2a4a3b1561bb766"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4ab37e4f4a33c64d9e565dc8c4c3ed774f05c0e3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/53b21bc2df6e8ed538bceda93a5104a5fe6a8a84"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8407a2c1aa67c2a110a576df8f82a4e259188b82"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8ec454dcd00ce3375119111c6394964455b36d0d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8fe3d6717f5536793727e60b7a0b7ec20c697def"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a43d96620d080b1b2324a53e38dd7b4bff4825c1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/de83419b5062a6f83bb9421be77cae734cbead65"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98934.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98934"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"d58e468b1112dcd1d5193c0a89ff9f98b5a3e8b9"},{"fixed":"de83419b5062a6f83bb9421be77cae734cbead65"},{"fixed":"8407a2c1aa67c2a110a576df8f82a4e259188b82"},{"fixed":"a43d96620d080b1b2324a53e38dd7b4bff4825c1"},{"fixed":"4ab37e4f4a33c64d9e565dc8c4c3ed774f05c0e3"},{"fixed":"8fe3d6717f5536793727e60b7a0b7ec20c697def"},{"fixed":"53b21bc2df6e8ed538bceda93a5104a5fe6a8a84"},{"fixed":"086e8acb3a0e55f6d22d29fae2a4a3b1561bb766"},{"fixed":"8ec454dcd00ce3375119111c6394964455b36d0d"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-98934.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.20.0"},{"fixed":"5.10.273"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.224"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.191"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.160"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.113"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.56"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-98934.json"}}],"schema_version":"1.9.2"}