smb: client: split cached_fid bitfields to avoid shared-byte RMW races
In the Linux kernel, the following vulnerability has been resolved: smb: client: split cached_fid bitfields to avoid shared-byte RMW races is_open, has_lease and on_list are stored in the same bitfield byte in struct cached_fid but are updated in different code paths that may run concurrently. Bitfield assignments generate byte read–modify–write operations (e.g. `orb $mask, addr` on x86_64), so updating one flag can restore stale values of the others. A possible interleaving is: CPU1: load old byte (has_lease=1, on_list=1) CPU2: clear both flags (store 0) CPU1: RMW store (old | IS_OPEN) -> reintroduces cleared bits To avoid this class of races, convert these flags to separate bool fields.
CVE-2026-23230
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-2026-23230
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": "ebe98f1447bbccf8228335c62d86af02a0ed23f7",
"lessThan": "569fecc56bfe4df66f05734d67daef887746656b",
"versionType": "git"
},
{
"status": "affected",
"version": "ebe98f1447bbccf8228335c62d86af02a0ed23f7",
"lessThan": "4386f6af8aaedd0c5ad6f659b40cadcc8f423828",
"versionType": "git"
},
{
"status": "affected",
"version": "ebe98f1447bbccf8228335c62d86af02a0ed23f7",
"lessThan": "3eaa22d688311c708b73f3c68bc6d0c8e3f0f77a",
"versionType": "git"
},
{
"status": "affected",
"version": "ebe98f1447bbccf8228335c62d86af02a0ed23f7",
"lessThan": "c4b9edd55987384a1f201d3d07ff71e448d79c1b",
"versionType": "git"
},
{
"status": "affected",
"version": "ebe98f1447bbccf8228335c62d86af02a0ed23f7",
"lessThan": "4cfa4c37dcbcfd70866e856200ed8a2894cac578",
"versionType": "git"
},
{
"status": "affected",
"version": "ebe98f1447bbccf8228335c62d86af02a0ed23f7",
"lessThan": "ec306600d5ba7148c9dbf8f5a8f1f5c1a044a241",
"versionType": "git"
}
],
"programFiles": [
"fs/smb/client/cached_dir.h"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.1"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.1",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.164",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.125",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.72",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.11",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "6.19.1",
"versionType": "semver",
"lessThanOrEqual": "6.19.*"
},
{
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/smb/client/cached_dir.h"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-23230
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #39822 · Revision 1
- Added to Heist Feed
- Publisher date