CVE-2026-23245 (GCVE-0-2026-23245)
Vulnerability from cvelistv5
Published
2026-03-18 10:05
Modified
2026-08-05 12:20
Summary
In the Linux kernel, the following vulnerability has been resolved: net/sched: act_gate: snapshot parameters with RCU on replace The gate action can be replaced while the hrtimer callback or dump path is walking the schedule list. Convert the parameters to an RCU-protected snapshot and swap updates under tcf_lock, freeing the previous snapshot via call_rcu(). When REPLACE omits the entry list, preserve the existing schedule so the effective state is unchanged.
Impacted products
Vendor Product Version
Linux Linux Version: a51c328df3106663879645680609eb49b3ff6444
Version: a51c328df3106663879645680609eb49b3ff6444
Version: a51c328df3106663879645680609eb49b3ff6444
Version: a51c328df3106663879645680609eb49b3ff6444
Version: a51c328df3106663879645680609eb49b3ff6444
Version: a51c328df3106663879645680609eb49b3ff6444
Version: a51c328df3106663879645680609eb49b3ff6444
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    "cveId": "CVE-2026-23245",
    "datePublished": "2026-03-18T10:05:07.406Z",
    "dateReserved": "2026-01-13T15:37:45.989Z",
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