{"id":"CVE-2024-56636","title":"geneve: do not assume mac header is set in geneve_xmit_skb()","summary":"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 …","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= a025fb5f49ad38cf749753b16fcd031d0d678f2b < d9fa09ca004befe9cf826d6820439cb6f93cecd7","Linux >= a025fb5f49ad38cf749753b16fcd031d0d678f2b < b65958284401016b983078c68f70b047537f4aba","Linux >= a025fb5f49ad38cf749753b16fcd031d0d678f2b < 2ee7bdc7cb40abfe658a71fbd10c7db2f4fc4f9a","Linux >= a025fb5f49ad38cf749753b16fcd031d0d678f2b < 97ce3a4ec55eac6b5e2949ffb04028d604afda3b","Linux >= a025fb5f49ad38cf749753b16fcd031d0d678f2b < 177b72ed7c77b11e46dd4336d73a87a77a5603af","Linux >= a025fb5f49ad38cf749753b16fcd031d0d678f2b < 8588c99c7d47448fcae39e3227d6e2bb97aad86d","Linux 5.0"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-05T20:29:27.955958Z"},"published":"2024-12-27","updated":"2026-11-05","sourceUpdated":"2026-11-05T20:31:25.382Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2024-56636","references":[{"url":"https://git.kernel.org/stable/c/d9fa09ca004befe9cf826d6820439cb6f93cecd7"},{"url":"https://git.kernel.org/stable/c/b65958284401016b983078c68f70b047537f4aba"},{"url":"https://git.kernel.org/stable/c/2ee7bdc7cb40abfe658a71fbd10c7db2f4fc4f9a"},{"url":"https://git.kernel.org/stable/c/97ce3a4ec55eac6b5e2949ffb04028d604afda3b"},{"url":"https://git.kernel.org/stable/c/177b72ed7c77b11e46dd4336d73a87a77a5603af"},{"url":"https://git.kernel.org/stable/c/8588c99c7d47448fcae39e3227d6e2bb97aad86d"}],"tags":["cve.org"],"epss":0.00268,"epssPercentile":0.19057,"ingestedAt":"2026-11-05T22:38:31.835Z","slug":"CVE-2024-56636","body":"## Overview\n\nIn 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 <0f> 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 <TASK>\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\n\n## Affected\n\n- `Linux >= a025fb5f49ad38cf749753b16fcd031d0d678f2b < d9fa09ca004befe9cf826d6820439cb6f93cecd7`\n- `Linux >= a025fb5f49ad38cf749753b16fcd031d0d678f2b < b65958284401016b983078c68f70b047537f4aba`\n- `Linux >= a025fb5f49ad38cf749753b16fcd031d0d678f2b < 2ee7bdc7cb40abfe658a71fbd10c7db2f4fc4f9a`\n- `Linux >= a025fb5f49ad38cf749753b16fcd031d0d678f2b < 97ce3a4ec55eac6b5e2949ffb04028d604afda3b`\n- `Linux >= a025fb5f49ad38cf749753b16fcd031d0d678f2b < 177b72ed7c77b11e46dd4336d73a87a77a5603af`\n- `Linux >= a025fb5f49ad38cf749753b16fcd031d0d678f2b < 8588c99c7d47448fcae39e3227d6e2bb97aad86d`\n- `Linux 5.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}