CVE-2026-97922tracing: Free histogram var refs regardless of how often they are referenced
- —Not scoredno CVSS score yet
- 0.21%Exploitation in 30 daysEPSS · top 89% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: tracing: Free histogram var refs regardless of how often they are referenced Using the same variable three or more times in one hist trigger leaks the variable reference and its strings when the trigger is removed. commit 656fe2ba85e8 ("tracing: Use hist trigger's var_ref array to destroy var_refs") made a trigger's var_refs[] array the only owner of a var ref: destroy_hist_field() returns early for HIST_FIELD_FL_VAR_REF, so the field expressions never destroy one. One entry, freed once, no count needed. commit 8bcebc77e85f ("tracing: Fix histogram code when expression has same var as value") then made repeated references share one object and added a count of them. Only the increment side exists, since those expressions still return early and never drop a reference, so __destroy_hist_field() sees how many references were created rather than how many are left. It frees when the decremented count is 0 or 1, so two references work and three or more leak. Sharing kept one array entry per object, and create_var_ref() searches and appends within a single trigger, so nothing outside it holds the object. Removing a trigger whose variables are still referenced is already refused by check_var_refs() with -EBUSY. Drop the count and free unconditionally.
Timeline
ID reserved
By Linux
Published
- 24 days later
· 24 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.
- EPSS (exploitation in 30 days)
- 0.21% · top 89% of all CVEs (14 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected 8bcebc77e85f3d7536f96845a0fe94b1dddb6af0 – < a1f1d64a0a9791c842c4646253daf6ac0313eac7
- affected 8bcebc77e85f3d7536f96845a0fe94b1dddb6af0 – < b513a4c60a7aa1f4b4c2a48544ab003cb36f1e94
- affected 8bcebc77e85f3d7536f96845a0fe94b1dddb6af0 – < e7b6d67b43caee9183a4374d23641578ea556e6c
- affected 8bcebc77e85f3d7536f96845a0fe94b1dddb6af0 – < 4cff53bb19412c6f2d90b50678de5c3903f7f96a
- affected 8bcebc77e85f3d7536f96845a0fe94b1dddb6af0 – < 94bbd65da4ae26592fa1977a74ee94218ab02a26
- affected 8bcebc77e85f3d7536f96845a0fe94b1dddb6af0 – < 4bddcb346a6cf4615ca77f69a589623b877ca267
- affected ce28d664054df01997baace61d1defca77689798
- affected bf470f051556b610265ea02ad2102de75e8e619c
- affected 4.19.100 – < 4.20
- affected 5.4.16 – < 5.5
- affected 5.5
- unaffected < 5.5
- unaffected 6.1.189 – ≤ 6.1.*
- unaffected 6.6.158 – ≤ 6.6.*
- unaffected 6.12.111 – ≤ 6.12.*
- unaffected 6.18.53 – ≤ 6.18.*
- unaffected 7.2.7 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References6
- https://git.kernel.org/stable/c/a1f1d64a0a9791c842c4646253daf6ac0313eac7 (opens in a new tab)
- https://git.kernel.org/stable/c/b513a4c60a7aa1f4b4c2a48544ab003cb36f1e94 (opens in a new tab)
- https://git.kernel.org/stable/c/e7b6d67b43caee9183a4374d23641578ea556e6c (opens in a new tab)
- https://git.kernel.org/stable/c/4cff53bb19412c6f2d90b50678de5c3903f7f96a (opens in a new tab)
- https://git.kernel.org/stable/c/94bbd65da4ae26592fa1977a74ee94218ab02a26 (opens in a new tab)
- https://git.kernel.org/stable/c/4bddcb346a6cf4615ca77f69a589623b877ca267 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-86776 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://cveledger.app/cve/CVE-2026-97922)Record last updated .