{"id":"CVE-2024-36927","summary":"ipv4: Fix uninit-value access in __ip_make_skb()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: Fix uninit-value access in __ip_make_skb()\n\nKMSAN reported uninit-value access in __ip_make_skb() [1].  __ip_make_skb()\ntests HDRINCL to know if the skb has icmphdr. However, HDRINCL can cause a\nrace condition. If calling setsockopt(2) with IP_HDRINCL changes HDRINCL\nwhile __ip_make_skb() is running, the function will access icmphdr in the\nskb even if it is not included. This causes the issue reported by KMSAN.\n\nCheck FLOWI_FLAG_KNOWN_NH on fl4-\u003eflowi4_flags instead of testing HDRINCL\non the socket.\n\nAlso, fl4-\u003efl4_icmp_type and fl4-\u003efl4_icmp_code are not initialized. These\nare union in struct flowi4 and are implicitly initialized by\nflowi4_init_output(), but we should not rely on specific union layout.\n\nInitialize these explicitly in raw_sendmsg().\n\n[1]\nBUG: KMSAN: uninit-value in __ip_make_skb+0x2b74/0x2d20 net/ipv4/ip_output.c:1481\n __ip_make_skb+0x2b74/0x2d20 net/ipv4/ip_output.c:1481\n ip_finish_skb include/net/ip.h:243 [inline]\n ip_push_pending_frames+0x4c/0x5c0 net/ipv4/ip_output.c:1508\n raw_sendmsg+0x2381/0x2690 net/ipv4/raw.c:654\n inet_sendmsg+0x27b/0x2a0 net/ipv4/af_inet.c:851\n sock_sendmsg_nosec net/socket.c:730 [inline]\n __sock_sendmsg+0x274/0x3c0 net/socket.c:745\n __sys_sendto+0x62c/0x7b0 net/socket.c:2191\n __do_sys_sendto net/socket.c:2203 [inline]\n __se_sys_sendto net/socket.c:2199 [inline]\n __x64_sys_sendto+0x130/0x200 net/socket.c:2199\n do_syscall_64+0xd8/0x1f0 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x6d/0x75\n\nUninit was created at:\n slab_post_alloc_hook mm/slub.c:3804 [inline]\n slab_alloc_node mm/slub.c:3845 [inline]\n kmem_cache_alloc_node+0x5f6/0xc50 mm/slub.c:3888\n kmalloc_reserve+0x13c/0x4a0 net/core/skbuff.c:577\n __alloc_skb+0x35a/0x7c0 net/core/skbuff.c:668\n alloc_skb include/linux/skbuff.h:1318 [inline]\n __ip_append_data+0x49ab/0x68c0 net/ipv4/ip_output.c:1128\n ip_append_data+0x1e7/0x260 net/ipv4/ip_output.c:1365\n raw_sendmsg+0x22b1/0x2690 net/ipv4/raw.c:648\n inet_sendmsg+0x27b/0x2a0 net/ipv4/af_inet.c:851\n sock_sendmsg_nosec net/socket.c:730 [inline]\n __sock_sendmsg+0x274/0x3c0 net/socket.c:745\n __sys_sendto+0x62c/0x7b0 net/socket.c:2191\n __do_sys_sendto net/socket.c:2203 [inline]\n __se_sys_sendto net/socket.c:2199 [inline]\n __x64_sys_sendto+0x130/0x200 net/socket.c:2199\n do_syscall_64+0xd8/0x1f0 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x6d/0x75\n\nCPU: 1 PID: 15709 Comm: syz-executor.7 Not tainted 6.8.0-11567-gb3603fcb79b1 #25\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014","modified":"2026-03-20T12:36:52.660766Z","published":"2024-05-30T15:29:20.275Z","related":["ALSA-2024:5101","MGASA-2024-0263","MGASA-2024-0266","SUSE-SU-2024:4314-1","SUSE-SU-2024:4316-1","SUSE-SU-2024:4318-1","SUSE-SU-2024:4387-1","SUSE-SU-2025:20163-1","SUSE-SU-2025:20164-1","SUSE-SU-2025:20246-1","SUSE-SU-2025:20247-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/36xxx/CVE-2024-36927.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/20d3eb00ab81462d554ac6d09691b8d9aa5a5741"},{"type":"WEB","url":"https://git.kernel.org/stable/c/55bf541e018b76b3750cb6c6ea18c46e1ac5562e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5db08343ddb1b239320612036c398e4e1bb52818"},{"type":"WEB","url":"https://git.kernel.org/stable/c/88c66f1879f322f11de34d37b2d3d87497afdcb6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f5c603ad4e6fcf42f84053e882ebe20184bb309e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fc1092f51567277509563800a3c56732070b6aa4"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/08/msg00010.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/36xxx/CVE-2024-36927.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-36927"},{"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":"566785731c6dd41ef815196ddc36d1ae30a63763"},{"fixed":"88c66f1879f322f11de34d37b2d3d87497afdcb6"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"a54ec573d9b81b05d368f8e6edc1b3e49f688658"},{"fixed":"20d3eb00ab81462d554ac6d09691b8d9aa5a5741"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"fc60067260c20da8cddcf968bec47416f3e2cde2"},{"fixed":"55bf541e018b76b3750cb6c6ea18c46e1ac5562e"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"99e5acae193e369b71217efe6f1dad42f3f18815"},{"fixed":"5db08343ddb1b239320612036c398e4e1bb52818"},{"fixed":"f5c603ad4e6fcf42f84053e882ebe20184bb309e"},{"fixed":"fc1092f51567277509563800a3c56732070b6aa4"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0"},{"last_affected":"dc4e3bb0710178c8d03fc43064e0a71fe7440cdd"},{"last_affected":"022ea4374c319690c804706bda9dc42946d1556d"},{"last_affected":"27c468ec1af113f6ae94fb5378f65e6038bd16e7"},{"last_affected":"32a5a13d556e4f804e5a447a08c70b172d600707"},{"last_affected":"9e3c96aed8fe32907e0a4bca05aad457629a820c"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-36927.json"}}],"schema_version":"1.7.5"}