CVE-2026-98076tracing/probes: Fix use-after-free on field name/type of events with multiple probes
- —Not scoredno CVSS score yet
- 0.22%Exploitation in 30 daysEPSS · top 88% 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/probes: Fix use-after-free on field name/type of events with multiple probes The fields of a probe-based dynamic event (kprobe, uprobe, eprobe and fprobe events) are created in traceprobe_define_arg_fields() by handing the probe_arg name/type strings to trace_define_field(), which only stores the pointers without copying. Those strings are owned by the trace_probe and are freed when that probe is removed. An event can have several probes attached. The field list is defined only once, by the first probe that registers the event, but it is kept alive by any surviving sibling probe. Deleting just that first probe by symbol - # primary A: fields are defined from A's args echo 'p:kprobes/ev vfs_read a1=$arg1' > kprobe_events # append B: shares A's event call echo 'p:kprobes/ev vfs_write a1=$arg1' >> kprobe_events # delete only A (matched by symbol), B survives echo '-:kprobes/ev vfs_read' >> kprobe_events frees A's args (trace_probe_cleanup() -> traceprobe_free_probe_arg()), but trace_probe_unlink() keeps the trace_probe_event because the probe list is not empty. The event call stays registered via B while its fields now reference freed memory. Any field lookup then reads it, e.g. echo 'a1 == 1' > events/kprobes/ev/filter BUG: KASAN: slab-use-after-free in strcmp+0xa7/0xb0 Call Trace: strcmp trace_find_event_field parse_pred process_preds create_filter apply_event_filter event_filter_write field->name references parg->name (kstrdup'd, freed with the probe) and, for array arguments, field->type references parg->fmt (kmalloc'd, freed with the probe) - the scalar type otherwise points at the static fmttype rodata, which is safe. Have traceprobe_define_arg_fields() duplicate the name and type strings and anchor the copies on the trace_probe_event, which embeds the event call and outlives every individual probe; trace_probe_event_free() releases them. The reproducer above triggers reliably; the field lookup and the delete both run under event_mutex, so this is a dangling reference after removal rather than a race. The issue was found by the autokbug dynamic kernel fuzzer at Tencent Yunding Lab.
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: Undergoing Analysis.
- EPSS (exploitation in 30 days)
- 0.22% · top 88% of all CVEs (15 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected ca89bc071d5e4e981dcc52e0ca90f4500d332e42 – < 38305e1b8b1ec27eef8f2d4e461e3b6c8624d494
- affected ca89bc071d5e4e981dcc52e0ca90f4500d332e42 – < 6d6118c17bc791594cbfd9cc4936ee21073b894a
- affected ca89bc071d5e4e981dcc52e0ca90f4500d332e42 – < a2510fcaad92b09b34574c97e8356234c6a84a9a
- affected ca89bc071d5e4e981dcc52e0ca90f4500d332e42 – < 9379e193826f23876daccb3351fab89c87084ba3
- affected ca89bc071d5e4e981dcc52e0ca90f4500d332e42 – < 68ae584169c7a41fc9bc4677c1d368983cf44b21
- affected ca89bc071d5e4e981dcc52e0ca90f4500d332e42 – < 411c9080a776577664531b4f7d3ee53b7a747ba8
- affected ca89bc071d5e4e981dcc52e0ca90f4500d332e42 – < 178ff2e011e21fbebdf57f5d58a408fe59136d82
- affected ca89bc071d5e4e981dcc52e0ca90f4500d332e42 – < 86b7a239ec6b14a7544200ede85474c6f5526049
- affected 5.4
- unaffected < 5.4
- unaffected 5.10.271 – ≤ 5.10.*
- unaffected 5.15.222 – ≤ 5.15.*
- 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
References8
- https://git.kernel.org/stable/c/38305e1b8b1ec27eef8f2d4e461e3b6c8624d494 (opens in a new tab)
- https://git.kernel.org/stable/c/6d6118c17bc791594cbfd9cc4936ee21073b894a (opens in a new tab)
- https://git.kernel.org/stable/c/a2510fcaad92b09b34574c97e8356234c6a84a9a (opens in a new tab)
- https://git.kernel.org/stable/c/9379e193826f23876daccb3351fab89c87084ba3 (opens in a new tab)
- https://git.kernel.org/stable/c/68ae584169c7a41fc9bc4677c1d368983cf44b21 (opens in a new tab)
- https://git.kernel.org/stable/c/411c9080a776577664531b4f7d3ee53b7a747ba8 (opens in a new tab)
- https://git.kernel.org/stable/c/178ff2e011e21fbebdf57f5d58a408fe59136d82 (opens in a new tab)
- https://git.kernel.org/stable/c/86b7a239ec6b14a7544200ede85474c6f5526049 (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-2026-86906 (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-2026-98076)Record last updated .