Medium 5.5Published Jul 19, 2026

CVE-2026-64028tracing: Avoid NULL return from hist_field_name() on truncation

Updated under an hour ago (Oct 27, 2026, 1:50 AM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: tracing: Avoid NULL return from hist_field_name() on truncation hist_field_name() returns "" everywhere except the fully-qualified VAR_REF/EXPR case, where snprintf() truncation returns NULL early and bypasses the bottom NULL->"" guard. Callers don't expect NULL: strcat(expr, hist_field_name(field, 0)) at trace_events_hist.c:1758 and the strcmp() in the sort-key match loop at :4804 both deref it. system and event_name are bounded by MAX_EVENT_NAME_LEN, but the field name on a VAR_REF is kstrdup'd from a histogram variable name parsed out of the trigger string and has no length cap, so a long enough var name in a fully qualified reference can reach the truncation path. Keep the length check but leave field_name as "" on overflow.

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: Jul 19, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 2e8578364061c4e88ae33bc20c2d6f64f365f6a2 before e3f5d42cdc2f167719564693675f1eead81378ea; from dfd1cd57ee6067301841b7b0967c70f910a51150 before 37377b39ff86dacbc533275c1155210d4fd5dc91; from e5c223f46c2e0691461dd97510c15e1f77148872 before 0402a1d3ddec565132867337ed44514a09d84728; from 9399a92989354e34086f9a5c379493217df83c5e before e91687643c440ca3997d67646e6f80b92edc6703; from 3cb6cb9c5a547a1979ad74f38eefe8e3687d96e0 before be4e99038c1603fa6b329d8ee3e364825e17c353; from 0402c60abe769098d77f3b3bd1e29a97922b614b before d6c8b3ebdcdb12b59ad4212acb137cc56cae453d; 6929e650db8451a9975ac0a631ba2d6e5d1e80ba builds before 915c1254fe0788abddc31095b360e9dc98907a34; from 5ec1d1e97de134beed3a5b08235a60fc1c51af96 before 576ec047d20b368b43c4d5db98c4f2e0f3c101ec	CNA record
linux linux_kernel linux:linux_kernel	6.6.141; 6.12.91; 6.18.33; 7.0.10; 7.1; 7.1; 7.1; 7.1	NVD

References

References

https://git.kernel.org/stable/c/e3f5d42cdc2f167719564693675f1eead81378ea	patch
https://git.kernel.org/stable/c/37377b39ff86dacbc533275c1155210d4fd5dc91	patch
https://git.kernel.org/stable/c/0402a1d3ddec565132867337ed44514a09d84728	patch
https://git.kernel.org/stable/c/e91687643c440ca3997d67646e6f80b92edc6703	patch
https://git.kernel.org/stable/c/be4e99038c1603fa6b329d8ee3e364825e17c353	patch
https://git.kernel.org/stable/c/d6c8b3ebdcdb12b59ad4212acb137cc56cae453d	patch
https://git.kernel.org/stable/c/915c1254fe0788abddc31095b360e9dc98907a34	patch
https://git.kernel.org/stable/c/576ec047d20b368b43c4d5db98c4f2e0f3c101ec	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.