{"id":"CVE-2024-26633","summary":"ip6_tunnel: fix NEXTHDR_FRAGMENT handling in ip6_tnl_parse_tlv_enc_lim()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nip6_tunnel: fix NEXTHDR_FRAGMENT handling in ip6_tnl_parse_tlv_enc_lim()\n\nsyzbot pointed out [1] that NEXTHDR_FRAGMENT handling is broken.\n\nReading frag_off can only be done if we pulled enough bytes\nto skb-\u003ehead. Currently we might access garbage.\n\n[1]\nBUG: KMSAN: uninit-value in ip6_tnl_parse_tlv_enc_lim+0x94f/0xbb0\nip6_tnl_parse_tlv_enc_lim+0x94f/0xbb0\nipxip6_tnl_xmit net/ipv6/ip6_tunnel.c:1326 [inline]\nip6_tnl_start_xmit+0xab2/0x1a70 net/ipv6/ip6_tunnel.c:1432\n__netdev_start_xmit include/linux/netdevice.h:4940 [inline]\nnetdev_start_xmit include/linux/netdevice.h:4954 [inline]\nxmit_one net/core/dev.c:3548 [inline]\ndev_hard_start_xmit+0x247/0xa10 net/core/dev.c:3564\n__dev_queue_xmit+0x33b8/0x5130 net/core/dev.c:4349\ndev_queue_xmit include/linux/netdevice.h:3134 [inline]\nneigh_connected_output+0x569/0x660 net/core/neighbour.c:1592\nneigh_output include/net/neighbour.h:542 [inline]\nip6_finish_output2+0x23a9/0x2b30 net/ipv6/ip6_output.c:137\nip6_finish_output+0x855/0x12b0 net/ipv6/ip6_output.c:222\nNF_HOOK_COND include/linux/netfilter.h:303 [inline]\nip6_output+0x323/0x610 net/ipv6/ip6_output.c:243\ndst_output include/net/dst.h:451 [inline]\nip6_local_out+0xe9/0x140 net/ipv6/output_core.c:155\nip6_send_skb net/ipv6/ip6_output.c:1952 [inline]\nip6_push_pending_frames+0x1f9/0x560 net/ipv6/ip6_output.c:1972\nrawv6_push_pending_frames+0xbe8/0xdf0 net/ipv6/raw.c:582\nrawv6_sendmsg+0x2b66/0x2e70 net/ipv6/raw.c:920\ninet_sendmsg+0x105/0x190 net/ipv4/af_inet.c:847\nsock_sendmsg_nosec net/socket.c:730 [inline]\n__sock_sendmsg net/socket.c:745 [inline]\n____sys_sendmsg+0x9c2/0xd60 net/socket.c:2584\n___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638\n__sys_sendmsg net/socket.c:2667 [inline]\n__do_sys_sendmsg net/socket.c:2676 [inline]\n__se_sys_sendmsg net/socket.c:2674 [inline]\n__x64_sys_sendmsg+0x307/0x490 net/socket.c:2674\ndo_syscall_x64 arch/x86/entry/common.c:52 [inline]\ndo_syscall_64+0x44/0x110 arch/x86/entry/common.c:83\nentry_SYSCALL_64_after_hwframe+0x63/0x6b\n\nUninit was created at:\nslab_post_alloc_hook+0x129/0xa70 mm/slab.h:768\nslab_alloc_node mm/slub.c:3478 [inline]\n__kmem_cache_alloc_node+0x5c9/0x970 mm/slub.c:3517\n__do_kmalloc_node mm/slab_common.c:1006 [inline]\n__kmalloc_node_track_caller+0x118/0x3c0 mm/slab_common.c:1027\nkmalloc_reserve+0x249/0x4a0 net/core/skbuff.c:582\npskb_expand_head+0x226/0x1a00 net/core/skbuff.c:2098\n__pskb_pull_tail+0x13b/0x2310 net/core/skbuff.c:2655\npskb_may_pull_reason include/linux/skbuff.h:2673 [inline]\npskb_may_pull include/linux/skbuff.h:2681 [inline]\nip6_tnl_parse_tlv_enc_lim+0x901/0xbb0 net/ipv6/ip6_tunnel.c:408\nipxip6_tnl_xmit net/ipv6/ip6_tunnel.c:1326 [inline]\nip6_tnl_start_xmit+0xab2/0x1a70 net/ipv6/ip6_tunnel.c:1432\n__netdev_start_xmit include/linux/netdevice.h:4940 [inline]\nnetdev_start_xmit include/linux/netdevice.h:4954 [inline]\nxmit_one net/core/dev.c:3548 [inline]\ndev_hard_start_xmit+0x247/0xa10 net/core/dev.c:3564\n__dev_queue_xmit+0x33b8/0x5130 net/core/dev.c:4349\ndev_queue_xmit include/linux/netdevice.h:3134 [inline]\nneigh_connected_output+0x569/0x660 net/core/neighbour.c:1592\nneigh_output include/net/neighbour.h:542 [inline]\nip6_finish_output2+0x23a9/0x2b30 net/ipv6/ip6_output.c:137\nip6_finish_output+0x855/0x12b0 net/ipv6/ip6_output.c:222\nNF_HOOK_COND include/linux/netfilter.h:303 [inline]\nip6_output+0x323/0x610 net/ipv6/ip6_output.c:243\ndst_output include/net/dst.h:451 [inline]\nip6_local_out+0xe9/0x140 net/ipv6/output_core.c:155\nip6_send_skb net/ipv6/ip6_output.c:1952 [inline]\nip6_push_pending_frames+0x1f9/0x560 net/ipv6/ip6_output.c:1972\nrawv6_push_pending_frames+0xbe8/0xdf0 net/ipv6/raw.c:582\nrawv6_sendmsg+0x2b66/0x2e70 net/ipv6/raw.c:920\ninet_sendmsg+0x105/0x190 net/ipv4/af_inet.c:847\nsock_sendmsg_nosec net/socket.c:730 [inline]\n__sock_sendmsg net/socket.c:745 [inline]\n____sys_sendmsg+0x9c2/0xd60 net/socket.c:2584\n___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638\n__sys_sendmsg net/socket.c:2667 [inline]\n__do_sys_sendms\n---truncated---","modified":"2026-04-02T10:05:07.488855Z","published":"2024-03-18T10:07:49.468Z","related":["ALSA-2024:2394","SUSE-SU-2024:2360-1","SUSE-SU-2024:2381-1","SUSE-SU-2024:2561-1","SUSE-SU-2024:2802-1","SUSE-SU-2024:2894-1","SUSE-SU-2024:2896-1","SUSE-SU-2024:2939-1","SUSE-SU-2024:2947-1","SUSE-SU-2024:2973-1","SUSE-SU-2025:20008-1","SUSE-SU-2025:20028-1","USN-6818-2","USN-6819-2"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/26xxx/CVE-2024-26633.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/135414f300c5db995e2a2f3bf0f455de9d014aee"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3f15ba3dc14e6ee002ea01b4faddc3d49200377c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4329426cf6b8e22b798db2331c7ef1dd2a9c748d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/62a1fedeb14c7ac0947ef33fadbabd35ed2400a2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/687c5d52fe53e602e76826dbd4d7af412747e183"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ba8d904c274268b18ef3dc11d3ca7b24a96cb087"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d375b98e0248980681e5e56b712026174d617198"},{"type":"WEB","url":"https://git.kernel.org/stable/c/da23bd709b46168f7dfc36055801011222b076cd"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2024/06/msg00016.html"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/26xxx/CVE-2024-26633.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-26633"},{"type":"ADVISORY","url":"https://security.netapp.com/advisory/ntap-20241220-0001/"},{"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":"fbfa743a9d2a0ffa24251764f10afc13eb21e739"},{"fixed":"135414f300c5db995e2a2f3bf0f455de9d014aee"},{"fixed":"3f15ba3dc14e6ee002ea01b4faddc3d49200377c"},{"fixed":"da23bd709b46168f7dfc36055801011222b076cd"},{"fixed":"4329426cf6b8e22b798db2331c7ef1dd2a9c748d"},{"fixed":"62a1fedeb14c7ac0947ef33fadbabd35ed2400a2"},{"fixed":"687c5d52fe53e602e76826dbd4d7af412747e183"},{"fixed":"ba8d904c274268b18ef3dc11d3ca7b24a96cb087"},{"fixed":"d375b98e0248980681e5e56b712026174d617198"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0"},{"last_affected":"a6f6bb6bc04a5f88a31f47a6123d3fbf5ee8d694"},{"last_affected":"72bbf335e7aad09c88c50dbdd238f4faabd12174"},{"last_affected":"decccc92ee0a978a1c268b5df16824cb6384ed3c"},{"last_affected":"d3d9b59ab32160e3cc4edcf7e5fa7cecb53a7d25"},{"last_affected":"d397f7035d2c754781bbe93b07b94d8cd898620c"},{"last_affected":"41e07a7e01d951cfd4c9a7dac90c921269d89513"},{"last_affected":"a7fe4e5d06338e1a82b1977eca37400951f99730"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-26633.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}