{"cve":"CVE-2022-49663","nvd":{"published":"2025-02-26T07:01:41.323","modified":"2026-06-17T05:18:47.080","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntunnels: do not assume mac header is set in skb_tunnel_check_pmtu()\n\nRecently added debug in commit f9aefd6b2aa3 (\"net: warn if mac header\nwas not set\") caught a bug in skb_tunnel_check_pmtu(), as shown\nin this syzbot report [1].\n\nIn ndo_start_xmit() paths, there is really no need to use skb->mac_header,\nbecause skb->data is supposed to point at it.\n\n[1] WARNING: CPU: 1 PID: 8604 at include/linux/skbuff.h:2784 skb_mac_header_len include/linux/skbuff.h:2784 [inline]\nWARNING: CPU: 1 PID: 8604 at include/linux/skbuff.h:2784 skb_tunnel_check_pmtu+0x5de/0x2f90 net/ipv4/ip_tunnel_core.c:413\nModules linked in:\nCPU: 1 PID: 8604 Comm: syz-executor.3 Not tainted 5.19.0-rc2-syzkaller-00443-g8720bd951b8e #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\nRIP: 0010:skb_mac_header_len include/linux/skbuff.h:2784 [inline]\nRIP: 0010:skb_tunnel_check_pmtu+0x5de/0x2f90 net/ipv4/ip_tunnel_core.c:413\nCode: 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 80 3c 02 00 0f 84 b9 fe ff ff 4c 89 ff e8 7c 0f d7 f9 e9 ac fe ff ff e8 c2 13 8a f9 <0f> 0b e9 28 fc ff ff e8 b6 13 8a f9 48 8b 54 24 70 48 b8 00 00 00\nRSP: 0018:ffffc90002e4f520 EFLAGS: 00010212\nRAX: 0000000000000324 RBX: ffff88804d5fd500 RCX: ffffc90005b52000\nRDX: 0000000000040000 RSI: ffffffff87f05e3e RDI: 0000000000000003\nRBP: ffffc90002e4f650 R08: 0000000000000003 R09: 000000000000ffff\nR10: 000000000000ffff R11: 0000000000000000 R12: 000000000000ffff\nR13: 0000000000000000 R14: 000000000000ffcd R15: 000000000000001f\nFS: 00007f3babba9700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000000020000080 CR3: 0000000075319000 CR4: 00000000003506e0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n<TASK>\ngeneve_xmit_skb drivers/net/geneve.c:927 [inline]\ngeneve_xmit+0xcf8/0x35d0 drivers/net/geneve.c:1107\n__netdev_start_xmit include/linux/netdevice.h:4805 [inline]\nnetdev_start_xmit include/linux/netdevice.h:4819 [inline]\n__dev_direct_xmit+0x500/0x730 net/core/dev.c:4309\ndev_direct_xmit include/linux/netdevice.h:3007 [inline]\npacket_direct_xmit+0x1b8/0x2c0 net/packet/af_packet.c:282\npacket_snd net/packet/af_packet.c:3073 [inline]\npacket_sendmsg+0x21f4/0x55d0 net/packet/af_packet.c:3104\nsock_sendmsg_nosec net/socket.c:714 [inline]\nsock_sendmsg+0xcf/0x120 net/socket.c:734\n____sys_sendmsg+0x6eb/0x810 net/socket.c:2489\n___sys_sendmsg+0xf3/0x170 net/socket.c:2543\n__sys_sendmsg net/socket.c:2572 [inline]\n__do_sys_sendmsg net/socket.c:2581 [inline]\n__se_sys_sendmsg net/socket.c:2579 [inline]\n__x64_sys_sendmsg+0x132/0x220 net/socket.c:2579\ndo_syscall_x64 arch/x86/entry/common.c:50 [inline]\ndo_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80\nentry_SYSCALL_64_after_hwframe+0x46/0xb0\nRIP: 0033:0x7f3baaa89109\nCode: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007f3babba9168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e\nRAX: ffffffffffffffda RBX: 00007f3baab9bf60 RCX: 00007f3baaa89109\nRDX: 0000000000000000 RSI: 0000000020000a00 RDI: 0000000000000003\nRBP: 00007f3baaae305d R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\nR13: 00007ffe74f2543f R14: 00007f3babba9300 R15: 0000000000022000\n</TASK>","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/32dcf62efa0003f92a976aea0c57f118e689de8b","https://git.kernel.org/stable/c/59c51c3b545128a92ebfb6dbae990d3abee110e7","https://git.kernel.org/stable/c/674a641e5b67e16ba3112eacd680ff87b38539de","https://git.kernel.org/stable/c/853a7614880231747040cada91d2b8d2e995c51a"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:59:48.811064707+00:00"},"epss":{"cve":"CVE-2022-49663","score":0.00273,"percentile":0.19739,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}