bpf: Fix bounds check for skb-backed dynptrs
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix bounds check for skb-backed dynptrs The skb_pointer_if_linear() function checks whether a memory region of length len starting at offset off into the skb is in the linear area, and returns a pointer to the region if so. The check currently subtracts between skb_headlen and offset of the check, and since skb_headlen is unsigned the subtraction can underflow. This causes the bounds check to spuriously pass and generate an arbitrary pointer of the form *(skb->data + off). The only user of this helper is currently skb-backed BPF dynptr code. Returning the wrong pointer leads to the dynptr erroneously being backed with invalid memory. Ensure the subtraction cannot underflow, and fail the check if it would. Use u64 arithmetic to also prevent overflow when calculating (skb_headlen(skb) - off) since off is unsigned.
CVE-2026-98591
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-2026-98591
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": "6f5a630d7c57cd79b1f526a95e757311e32d41e5",
"lessThan": "1b923538598be768e9f2f258a77a083d00e0c78b",
"versionType": "git"
},
{
"status": "affected",
"version": "6f5a630d7c57cd79b1f526a95e757311e32d41e5",
"lessThan": "37877a24758068742fef687a7cf5362360dde1d1",
"versionType": "git"
},
{
"status": "affected",
"version": "6f5a630d7c57cd79b1f526a95e757311e32d41e5",
"lessThan": "1196903a27cac5c929c7517e987a8d159f20c5e5",
"versionType": "git"
},
{
"status": "affected",
"version": "6f5a630d7c57cd79b1f526a95e757311e32d41e5",
"lessThan": "39ffceaddb10753eac12785dba6ac0673860b4ac",
"versionType": "git"
},
{
"status": "affected",
"version": "6f5a630d7c57cd79b1f526a95e757311e32d41e5",
"lessThan": "ed6eec97b534979dcf28b40c389cee57bd6561d4",
"versionType": "git"
}
],
"programFiles": [
"include/linux/skbuff.h"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.6"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.6",
"versionType": "semver"
},
{
"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": "6.18.55",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.9",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/linux/skbuff.h"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98591
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #38611 · Revision 1
- Added to Heist Feed
- Publisher date