{"id":"CVE-2024-56636","summary":"geneve: do not assume mac header is set in geneve_xmit_skb()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ngeneve: do not assume mac header is set in geneve_xmit_skb()\n\nWe should not assume mac header is set in output path.\n\nUse skb_eth_hdr() instead of eth_hdr() to fix the issue.\n\nsysbot reported the following :\n\n WARNING: CPU: 0 PID: 11635 at include/linux/skbuff.h:3052 skb_mac_header include/linux/skbuff.h:3052 [inline]\n WARNING: CPU: 0 PID: 11635 at include/linux/skbuff.h:3052 eth_hdr include/linux/if_ether.h:24 [inline]\n WARNING: CPU: 0 PID: 11635 at include/linux/skbuff.h:3052 geneve_xmit_skb drivers/net/geneve.c:898 [inline]\n WARNING: CPU: 0 PID: 11635 at include/linux/skbuff.h:3052 geneve_xmit+0x4c38/0x5730 drivers/net/geneve.c:1039\nModules linked in:\nCPU: 0 UID: 0 PID: 11635 Comm: syz.4.1423 Not tainted 6.12.0-syzkaller-10296-gaaf20f870da0 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024\n RIP: 0010:skb_mac_header include/linux/skbuff.h:3052 [inline]\n RIP: 0010:eth_hdr include/linux/if_ether.h:24 [inline]\n RIP: 0010:geneve_xmit_skb drivers/net/geneve.c:898 [inline]\n RIP: 0010:geneve_xmit+0x4c38/0x5730 drivers/net/geneve.c:1039\nCode: 21 c6 02 e9 35 d4 ff ff e8 a5 48 4c fb 90 0f 0b 90 e9 fd f5 ff ff e8 97 48 4c fb 90 0f 0b 90 e9 d8 f5 ff ff e8 89 48 4c fb 90 \u003c0f\u003e 0b 90 e9 41 e4 ff ff e8 7b 48 4c fb 90 0f 0b 90 e9 cd e7 ff ff\nRSP: 0018:ffffc90003b2f870 EFLAGS: 00010283\nRAX: 000000000000037a RBX: 000000000000ffff RCX: ffffc9000dc3d000\nRDX: 0000000000080000 RSI: ffffffff86428417 RDI: 0000000000000003\nRBP: ffffc90003b2f9f0 R08: 0000000000000003 R09: 000000000000ffff\nR10: 000000000000ffff R11: 0000000000000002 R12: ffff88806603c000\nR13: 0000000000000000 R14: ffff8880685b2780 R15: 0000000000000e23\nFS:  00007fdc2deed6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000001b30a1dff8 CR3: 0000000056b8c000 CR4: 00000000003526f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n \u003cTASK\u003e\n  __netdev_start_xmit include/linux/netdevice.h:5002 [inline]\n  netdev_start_xmit include/linux/netdevice.h:5011 [inline]\n  __dev_direct_xmit+0x58a/0x720 net/core/dev.c:4490\n  dev_direct_xmit include/linux/netdevice.h:3181 [inline]\n  packet_xmit+0x1e4/0x360 net/packet/af_packet.c:285\n  packet_snd net/packet/af_packet.c:3146 [inline]\n  packet_sendmsg+0x2700/0x5660 net/packet/af_packet.c:3178\n  sock_sendmsg_nosec net/socket.c:711 [inline]\n  __sock_sendmsg net/socket.c:726 [inline]\n  __sys_sendto+0x488/0x4f0 net/socket.c:2197\n  __do_sys_sendto net/socket.c:2204 [inline]\n  __se_sys_sendto net/socket.c:2200 [inline]\n  __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2200\n  do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n  do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f","modified":"2026-05-18T05:56:11.586884497Z","published":"2024-12-27T15:02:38.946Z","related":["SUSE-SU-2025:0289-1","SUSE-SU-2025:0428-1","SUSE-SU-2025:0499-1","SUSE-SU-2025:0557-1","SUSE-SU-2025:20165-1","SUSE-SU-2025:20166-1","SUSE-SU-2025:20248-1","SUSE-SU-2025:20249-1","USN-7379-2","USN-7380-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/56xxx/CVE-2024-56636.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/177b72ed7c77b11e46dd4336d73a87a77a5603af"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2ee7bdc7cb40abfe658a71fbd10c7db2f4fc4f9a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8588c99c7d47448fcae39e3227d6e2bb97aad86d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/97ce3a4ec55eac6b5e2949ffb04028d604afda3b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b65958284401016b983078c68f70b047537f4aba"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d9fa09ca004befe9cf826d6820439cb6f93cecd7"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/56xxx/CVE-2024-56636.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-56636"},{"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":"a025fb5f49ad38cf749753b16fcd031d0d678f2b"},{"fixed":"d9fa09ca004befe9cf826d6820439cb6f93cecd7"},{"fixed":"b65958284401016b983078c68f70b047537f4aba"},{"fixed":"2ee7bdc7cb40abfe658a71fbd10c7db2f4fc4f9a"},{"fixed":"97ce3a4ec55eac6b5e2949ffb04028d604afda3b"},{"fixed":"177b72ed7c77b11e46dd4336d73a87a77a5603af"},{"fixed":"8588c99c7d47448fcae39e3227d6e2bb97aad86d"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-56636.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.0.0"},{"fixed":"5.10.231"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.174"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.120"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.66"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-56636.json"}}],"schema_version":"1.7.5"}