SUNRPC: harden gss_unwrap_resp_priv length checks
In the Linux kernel, the following vulnerability has been resolved: SUNRPC: harden gss_unwrap_resp_priv length checks gss_unwrap_resp_priv() validates the RPCSEC_GSS opaque length with offset = (u8 *)(p) - (u8 *)head->iov_base; if (offset + opaque_len > rcv_buf->len) goto unwrap_failed; maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, offset + opaque_len, rcv_buf); Both operands are u32 and the sum is computed in u32. A reply with opaque_len near 0xffffffff makes offset + opaque_len wrap to a small value that is below rcv_buf->len, so the bound check passes and gss_unwrap() is called with end < begin. The check also lacks a lower bound, so any opaque_len in [0, GSS_KRB5_TOK_HDR_LEN) is accepted and forwarded to gss_krb5_unwrap_v2(), whose pre-decrypt header reads at ptr+4 and ptr+6 then run past the token. A krb5p NFS server returning a crafted RPCSEC_GSS reply can drive the client into out-of-bounds reads in gss_krb5_unwrap_v2() and the rotate_left() loop that follows. Fix by replacing the single combined check with three guards that are safe in u32 arithmetic and that enforce the RFC 4121 minimum outer token length: if (offset > rcv_buf->len) goto unwrap_failed; if (opaque_len > rcv_buf->len - offset) goto unwrap_failed; if (opaque_len < GSS_KRB5_TOK_HDR_LEN) goto unwrap_failed; The first guard makes the subtraction in the second guard unconditionally safe; offset is derived from a successful xdr_inline_decode() in the head kvec, so in practice it already satisfies the bound.
CVE-2026-89541
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-2026-89541
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": "2d2da60c63b67174add32f06e8d54c3a0c5cd9cf",
"lessThan": "3691c4b3488d8ca046b9941e5be30c626dbbbb50",
"versionType": "git"
},
{
"status": "affected",
"version": "2d2da60c63b67174add32f06e8d54c3a0c5cd9cf",
"lessThan": "85fa6b12e8f439739ac36ef2aad925f37c8b976a",
"versionType": "git"
},
{
"status": "affected",
"version": "2d2da60c63b67174add32f06e8d54c3a0c5cd9cf",
"lessThan": "401f6a5b338d05bb1069ad814d9f77e3c367854f",
"versionType": "git"
},
{
"status": "affected",
"version": "2d2da60c63b67174add32f06e8d54c3a0c5cd9cf",
"lessThan": "81fd7654a8429718adfcb2a7e03496077f547ed0",
"versionType": "git"
},
{
"status": "affected",
"version": "2d2da60c63b67174add32f06e8d54c3a0c5cd9cf",
"lessThan": "89a15a50f84d32d4b99db86f957427fcbe20a99a",
"versionType": "git"
},
{
"status": "affected",
"version": "2d2da60c63b67174add32f06e8d54c3a0c5cd9cf",
"lessThan": "ebcbd2523a8524c3d24e111cdbed8e271d910269",
"versionType": "git"
},
{
"status": "affected",
"version": "2d2da60c63b67174add32f06e8d54c3a0c5cd9cf",
"lessThan": "d395c30d570ca6168f0297b191709927d1258273",
"versionType": "git"
},
{
"status": "affected",
"version": "2d2da60c63b67174add32f06e8d54c3a0c5cd9cf",
"lessThan": "87831b92112c81db251d46756d65daa4f91af6a2",
"versionType": "git"
}
],
"programFiles": [
"net/sunrpc/auth_gss/auth_gss.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.15"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.15",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.270",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.221",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.109",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.50",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/sunrpc/auth_gss/auth_gss.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-89541
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #35059 · Revision 1
- Added to Heist Feed
- Publisher date