arm64: tlb: Flush walk cache when unsharing PMD tables
In the Linux kernel, the following vulnerability has been resolved: arm64: tlb: Flush walk cache when unsharing PMD tables When huge_pmd_unshare() is called to unshare a PMD table, the tlb_unshare_pmd_ptdesc() function sets tlb->unshared_tables=true but the aarch64 tlb_flush() only checked tlb->freed_tables to determine whether to use TLBF_NONE (vae1is, invalidates walk cache) or TLBF_NOWALKCACHE (vale1is, leaf-only). This caused the stale PMD page table entry to remain in the walk cache after unshare, potentially leading to incorrect page table walks. Fix by including unshared_tables in the check, so that when unsharing tables, TLBF_NONE is used and the walk cache is properly invalidated. Here is the detailed distinction between vae1is and vale1is: | Instruction Combination | Actual Invalidation Scope | | ------------------------ | --------------------------------------------------| | `VAE1IS` + TTL=`0` | All entries at all levels (full invalidation) | | `VAE1IS` + TTL=`2` (L2) | Non-leaf at Level 0/1 + leaf at Level 2 | | `VALE1IS` + TTL=`0` | Leaf entries at all levels (non-leaf not cleared) | | `VALE1IS` + TTL=`2` (L2) | Leaf entry at Level 2 only |
CVE-2026-63875
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-2026-63875
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": "6495204f8219a57859669d618b25d06176d5a872",
"lessThan": "dced308d7d6a0de1c09d2058f38f1aaaf5cbb914",
"versionType": "git"
},
{
"status": "affected",
"version": "ce4cf24761467756462c0e1dbe4a5e9c9eb520fc",
"lessThan": "47490bbb05c8c0e09cc3cfd237d8934ffc340583",
"versionType": "git"
},
{
"status": "affected",
"version": "daa6707b71a2da23a82979fa21f788aeb706f1a2",
"lessThan": "0199c9d57861f17b556b6cba1f765c7cce79745b",
"versionType": "git"
},
{
"status": "affected",
"version": "ff37dd18ce7739a26aab0cc2d31006a45e6bde63",
"lessThan": "d766a49d9b55705c4737cd8bb5d3faa2d31330fd",
"versionType": "git"
},
{
"status": "affected",
"version": "da06bb0ca45b1ca6f1ab55023e34e61a520337f3",
"lessThan": "8ca7284da0e67b3e71d90ec17f08286774245ad9",
"versionType": "git"
},
{
"status": "affected",
"version": "9b671f6f432be07c0ddd66e437d6d0e0db684f83",
"lessThan": "fe93e907b1af03cc229a80aa64a570a103d2b279",
"versionType": "git"
},
{
"status": "affected",
"version": "8ce720d5bd91e9dc16db3604aa4b1bf76770a9a1",
"lessThan": "48125cd9c55cbe297b59fd1f9bda48b0960bd181",
"versionType": "git"
},
{
"status": "affected",
"version": "8ce720d5bd91e9dc16db3604aa4b1bf76770a9a1",
"lessThan": "c2ff4764e03e7a8d758352f4aceb8fe1be6ac971",
"versionType": "git"
},
{
"status": "affected",
"version": "5.10.253",
"lessThan": "5.10.259",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.15.203",
"lessThan": "5.15.210",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.1.167",
"lessThan": "6.1.176",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.6.127",
"lessThan": "6.6.143",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.12.74",
"lessThan": "6.12.93",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.18.13",
"lessThan": "6.18.35",
"versionType": "semver"
}
],
"programFiles": [
"arch/arm64/include/asm/tlb.h"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.19"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.19",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.259",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.210",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.176",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.143",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.93",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.35",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.12",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"arch/arm64/include/asm/tlb.h"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-63875
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #40877 · Revision 1
- Added to Heist Feed
- Publisher date