CVE-2026-80742
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: af_packet: Don't send zero-byte data in tpacket_snd(). syzbot reported a WARNING in __dev_queue_xmit() triggered via tpacket_snd(): skb_assert_len WARNING: at include/linux/skbuff.h:2753 skb_assert_len WARNING: at __dev_queue_xmit+0x21bc/0x4970 net/core/dev.c:4781 Call Trace: <TASK> dev_queue_xmit include/linux/netdevice.h:3448 [inline] packet_xmit+0x243/0x310 net/packet/af_packet.c:276 tpacket_snd net/packet/af_packet.c:2907 [inline] packet_sendmsg+0x28d6/0x4eb0 net/packet/af_packet.c:3134 When sending 0-byte packets via TPACKET ring buffer on devices with no hard header (e.g. dev->hard_header_len == 0), tpacket_fill_skb() populates an skb with skb->len == 0 and returns 0. tpacket_snd() then forwards this empty skb to packet_xmit(), causing __dev_queue_xmit() to hit skb_assert_len(skb). Similar checks exist in packet_snd() via commit dc633700f00f ("net/af_packet: check len when min_header_len equals to 0") and in packet_sendmsg_spkt() via commit 6a341729fb31 ("af_packet: Don't send zero-byte data in packet_sendmsg_spkt()."). Return -EINVAL in tpacket_fill_skb() when skb->len is zero to reject zero-length packets in tpacket_snd().
Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-09-03 13:06:13.437000
Last modified
2026-11-06 17:19:57.490000
View original CVE JSON
{
"id": "CVE-2026-80742",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-03T13:06:13.437",
"lastModified": "2026-11-06T17:19:57.490",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\naf_packet: Don't send zero-byte data in tpacket_snd().\n\nsyzbot reported a WARNING in __dev_queue_xmit() triggered via tpacket_snd():\n\nskb_assert_len\nWARNING: at include/linux/skbuff.h:2753 skb_assert_len\nWARNING: at __dev_queue_xmit+0x21bc/0x4970 net/core/dev.c:4781\n\nCall Trace:\n <TASK>\n dev_queue_xmit include/linux/netdevice.h:3448 [inline]\n packet_xmit+0x243/0x310 net/packet/af_packet.c:276\n tpacket_snd net/packet/af_packet.c:2907 [inline]\n packet_sendmsg+0x28d6/0x4eb0 net/packet/af_packet.c:3134\n\nWhen sending 0-byte packets via TPACKET ring buffer on devices with no\nhard header (e.g. dev->hard_header_len == 0), tpacket_fill_skb()\npopulates an skb with skb->len == 0 and returns 0. tpacket_snd() then\nforwards this empty skb to packet_xmit(), causing __dev_queue_xmit() to\nhit skb_assert_len(skb).\n\nSimilar checks exist in packet_snd() via commit dc633700f00f\n(\"net/af_packet: check len when min_header_len equals to 0\") and in\npacket_sendmsg_spkt() via commit 6a341729fb31 (\"af_packet: Don't send\nzero-byte data in packet_sendmsg_spkt().\").\n\nReturn -EINVAL in tpacket_fill_skb() when skb->len is zero to reject\nzero-length packets in tpacket_snd()."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/packet/af_packet.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
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"lessThan": "dde212f8622f5cb36223fff1ebd6e6f2a3dc61fe",
"versionType": "git",
"status": "affected"
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{
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"versionType": "git",
"status": "affected"
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}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"net/packet/af_packet.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "2.6.12",
"status": "affected"
},
{
"version": "0",
"lessThan": "2.6.12",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.266",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.217",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.184",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.153",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.105",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.46",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.1.10",
"lessThanOrEqual": "7.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-11-06T17:02:59.452949Z",
"id": "CVE-2026-80742",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/1fc70b3d513bafb16b17540178870ef46e81c0bb",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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{
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}
]
}