linux — security advisory
In the Linux kernel, the following vulnerability has been resolved: tunnels: do not assume mac header is set in skb_tunnel_check_pmtu() Recently added debug in commit f9aefd6b2aa3 ("net: warn if mac header was not set") caught a bug in skb_tunnel_check_pmtu(), as shown in this syzbot report [1]. In ndo_start_xmit() paths, there is really no need to use skb->mac_header, because skb->data is supposed to point at it. [1] WARNING: CPU: 1 PID: 8604 at include/linux/skbuff.h:2784 skb_mac_header_len include/linux/skbuff.h:2784 [inline] WARNING: CPU: 1 PID: 8604 at include/linux/skbuff.h:2784 skb_tunnel_check_pmtu+0x5de/0x2f90 net/ipv4/ip_tunnel_core.c:413 Modules linked in: CPU: 1 PID: 8604 Comm: syz-executor.3 Not tainted 5.19.0-rc2-syzkaller-00443-g8720bd951b8e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:skb_mac_header_len include/linux/skbuff.h:2784 [inline] RIP: 0010:skb_tunnel_check_pmtu+0x5de/0x2f90 net/ipv4/ip_tunnel_core.c:413 Code: 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 RSP: 0018:ffffc90002e4f520 EFLAGS: 00010212 RAX: 0000000000000324 RBX: ffff88804d5fd500 RCX: ffffc90005b52000 RDX: 0000000000040000 RSI: ffffffff87f05e3e RDI: 0000000000000003 RBP: ffffc90002e4f650 R08: 0000000000000003 R09: 000000000000ffff R10: 000000000000ffff R11: 0000000000000000 R12: 00000000
- Products
- linux
- Affected versions
- Not specified
- Fixed versions
- 5.18.14-1
- CVEs
- CVE-2022-49663
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 30 Oct 2026, 15:26 UTC · Revision 1
Source evidence
In the Linux kernel, the following vulnerability has been resolved: tunnels: do not assume mac header is set in skb_tunnel_check_pmtu() Recently added debug in commit f9aefd6b2aa3 ("net: warn if mac header was not set") caught a bug in skb_tunnel_check_pmtu(), as shown in this syzbot report [1]. In ndo_start_xmit() paths, there is really no need to use skb->mac_header, because skb->data is supposed to point at it. [1] WARNING: CPU: 1 PID: 8604 at include/linux/skbuff.h:2784 skb_mac_header_len include/linux/skbuff.h:2784 [inline] WARNING: CPU: 1 PID: 8604 at include/linux/skbuff.h:2784 skb_tunnel_check_pmtu+0x5de/0x2f90 net/ipv4/ip_tunnel_core.c:413 Modules linked in: CPU: 1 PID: 8604 Comm: syz-executor.3 Not tainted 5.19.0-rc2-syzkaller-00443-g8720bd951b8e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:skb_mac_header_len include/linux/skbuff.h:2784 [inline] RIP: 0010:skb_tunnel_check_pmtu+0x5de/0x2f90 net/ipv4/ip_tunnel_core.c:413 Code: 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 RSP: 0018:ffffc90002e4f520 EFLAGS: 00010212 RAX: 0000000000000324 RBX: ffff88804d5fd500 RCX: ffffc90005b52000 RDX: 0000000000040000 RSI: ffffffff87f05e3e RDI: 0000000000000003 RBP: ffffc90002e4f650 R08: 0000000000000003 R09: 000000000000ffff R10: 000000000000ffff R11: 0000000000000000 R12: 00000000
osv:DEBIAN-CVE-2022-49663
linux
Fixed versions: 5.18.14-1
linux
Fixed versions: 5.18.14-1
linux
Fixed versions: 5.18.14-1
Complete source record
{
"id": "726a205e5abc78f08d44496c72055c3a8c1570c2b746f4265abbd6e44c23c9de",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2022-49663",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2022-49663",
"summary": "In the Linux kernel, the following vulnerability has been resolved: tunnels: do not assume mac header is set in skb_tunnel_check_pmtu() Recently added debug in commit f9aefd6b2aa3 (\"net: warn if mac header was not set\") caught a bug in skb_tunnel_check_pmtu(), as shown in this syzbot report [1]. In ndo_start_xmit() paths, there is really no need to use skb->mac_header, because skb->data is supposed to point at it. [1] WARNING: CPU: 1 PID: 8604 at include/linux/skbuff.h:2784 skb_mac_header_len include/linux/skbuff.h:2784 [inline] WARNING: CPU: 1 PID: 8604 at include/linux/skbuff.h:2784 skb_tunnel_check_pmtu+0x5de/0x2f90 net/ipv4/ip_tunnel_core.c:413 Modules linked in: CPU: 1 PID: 8604 Comm: syz-executor.3 Not tainted 5.19.0-rc2-syzkaller-00443-g8720bd951b8e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:skb_mac_header_len include/linux/skbuff.h:2784 [inline] RIP: 0010:skb_tunnel_check_pmtu+0x5de/0x2f90 net/ipv4/ip_tunnel_core.c:413 Code: 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 RSP: 0018:ffffc90002e4f520 EFLAGS: 00010212 RAX: 0000000000000324 RBX: ffff88804d5fd500 RCX: ffffc90005b52000 RDX: 0000000000040000 RSI: ffffffff87f05e3e RDI: 0000000000000003 RBP: ffffc90002e4f650 R08: 0000000000000003 R09: 000000000000ffff R10: 000000000000ffff R11: 0000000000000000 R12: 00000000",
"evidence": "osv:DEBIAN-CVE-2022-49663",
"products": [
{
"name": {
"value": "linux",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.18.14-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "linux",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.18.14-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "linux",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.18.14-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2022-49663",
"aliases": [
"DEBIAN-CVE-2022-49663"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.18.14-1"
}
]
}
],
"package": {
"name": "linux",
"purl": "pkg:deb/debian/linux?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49663.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.18.14-1"
}
]
}
],
"package": {
"name": "linux",
"purl": "pkg:deb/debian/linux?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49663.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.18.14-1"
}
]
}
],
"package": {
"name": "linux",
"purl": "pkg:deb/debian/linux?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49663.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-15T08:02:59.364824721Z",
"provider": "osv",
"upstream": [
"CVE-2022-49663"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2022-49663"
]
},
"related_cves": [
{
"value": "CVE-2022-49663",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 324846,
"published_at": "2025-02-26T07:01:41.323+00:00"
}