net: lan743x: fix RX checksum use-after-free
In the Linux kernel, the following vulnerability has been resolved: net: lan743x: fix RX checksum use-after-free lan743x_rx_process_buffer() adds each non-first receive buffer to the head skb's frag_list. On the last descriptor, lan743x_rx_trim_skb() linearizes the head and frees the fragment skb metadata. The checksum-success path then writes ip_summed through the local skb pointer, which still points to the final fragment. This causes a use-after-free write when a packet spans more than one receive buffer. Set ip_summed on the surviving head skb instead. Multi-buffer receive can occur after a live MTU increase because existing ring entries keep their old buffer size until they are replenished. A KUnit test invoking lan743x_rx_process_buffer() with a two-buffer packet produced a one-byte KASAN use-after-free write before this change. The same test passed after the change. The driver object also builds with W=1. This was not tested on physical LAN743x hardware.
CVE-2026-98239
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-2026-98239
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": "cd6910501cfd9a3bdff2f5fc33c9f3cf165ca54a",
"lessThan": "0e52886c4324c9897c2c62f92be3dc8316cee67e",
"versionType": "git"
},
{
"status": "affected",
"version": "cd6910501cfd9a3bdff2f5fc33c9f3cf165ca54a",
"lessThan": "a58024835c704419bb46d2a34e5223f65605f958",
"versionType": "git"
},
{
"status": "affected",
"version": "cd6910501cfd9a3bdff2f5fc33c9f3cf165ca54a",
"lessThan": "6fe5c3a2503983abb431d93faeadfc7f5e6a7e33",
"versionType": "git"
},
{
"status": "affected",
"version": "cd6910501cfd9a3bdff2f5fc33c9f3cf165ca54a",
"lessThan": "5c216bfa9fb7b36804485e67975e9c98055b31ef",
"versionType": "git"
},
{
"status": "affected",
"version": "cd6910501cfd9a3bdff2f5fc33c9f3cf165ca54a",
"lessThan": "161a403c8625e152de03d1da22bbf9cda6dc9f9f",
"versionType": "git"
},
{
"status": "affected",
"version": "cd6910501cfd9a3bdff2f5fc33c9f3cf165ca54a",
"lessThan": "a9ce4053dc945c5372dedba5017ee675b30dc0c5",
"versionType": "git"
}
],
"programFiles": [
"drivers/net/ethernet/microchip/lan743x_main.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.1"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.1",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.189",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.112",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.54",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.8",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/net/ethernet/microchip/lan743x_main.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98239
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #38319 · Revision 1
- Added to Heist Feed
- Publisher date