packet: use consistent hard_header_len in non-ring send paths
In the Linux kernel, the following vulnerability has been resolved: packet: use consistent hard_header_len in non-ring send paths packet_snd() reads dev->hard_header_len multiple times while allocating and constructing an skb. Device reconfiguration can change this value concurrently, for example through bonding device type changes. For SOCK_RAW, packet_snd() can save a larger value in reserve and later allocate headroom using a smaller value. Moving skb->data back by reserve then places it before skb->head, and the following copy from userspace can attempt an out-of-bounds write. packet_sendmsg_spkt() has the same issue because it calculates its reservation and header offset from separate reads before dropping the RCU read lock to allocate the skb. Add LL_RESERVED_SPACE_EX() for callers that already saved a header length. Read hard_header_len once in packet_snd() and use it for allocation and construction. In packet_sendmsg_spkt(), preserve the allocation-time value through the device lookup retry. The separate SOCK_DGRAM consistency problem between hard_header_len and header_ops->create is not addressed here.
CVE-2026-74582
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-74582
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba",
"lessThan": "bcd4df60ac9481b1ceffdfe5ec38fe51dcaae812",
"versionType": "git"
},
{
"status": "affected",
"version": "b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba",
"lessThan": "78a47127e33c340bc6d38dcc4552a094b4f5cc77",
"versionType": "git"
},
{
"status": "affected",
"version": "b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba",
"lessThan": "142e287b3a25cfe909215177c23243e7fc5ae2b1",
"versionType": "git"
},
{
"status": "affected",
"version": "b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba",
"lessThan": "91f041451f967cd87ed722a8f43c0b767a64f1a0",
"versionType": "git"
},
{
"status": "affected",
"version": "b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba",
"lessThan": "9052756290962ffb9a661bcf319e92dedaaedfed",
"versionType": "git"
},
{
"status": "affected",
"version": "b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba",
"lessThan": "5bb10753d428aadfc356a2bfe9acea09c82a62ec",
"versionType": "git"
},
{
"status": "affected",
"version": "b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba",
"lessThan": "b06b6fce6d7deaf7238e09b48ce3b1125ff41acd",
"versionType": "git"
},
{
"status": "affected",
"version": "b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba",
"lessThan": "03390aa32e669cc4ecd7d34108e2e1afc13d689d",
"versionType": "git"
},
{
"status": "affected",
"version": "d9fb8cc230b2a4757e9fe4f81468f81212d4deaa",
"versionType": "git"
},
{
"status": "affected",
"version": "6190cce26e40bf71c4d375b21eea74bb07b6a0f3",
"versionType": "git"
},
{
"status": "affected",
"version": "01a658c1b9d4b5393c38d5a92d9112ab1425382a",
"versionType": "git"
},
{
"status": "affected",
"version": "8809ae6747e760e6f1d2453ceb08c9bcc4939766",
"versionType": "git"
},
{
"status": "affected",
"version": "4.4.133",
"lessThan": "4.5",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.9.103",
"lessThan": "4.10",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.14.44",
"lessThan": "4.15",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.16.12",
"lessThan": "4.17",
"versionType": "semver"
}
],
"programFiles": [
"include/linux/netdevice.h",
"net/packet/af_packet.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.17"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.17",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.267",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.218",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.185",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.152",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.104",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.45",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.9",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/linux/netdevice.h",
"net/packet/af_packet.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-74582
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #33220 · Revision 1
- Added to Heist Feed
- Publisher date