CVE-2026-89580

CVE CVE-2026-89580EUVD EUVD-2026-76492Veröffentlicht 2026-09-11T19:44:46.000ZZuletzt geändert 2026-09-13T06:31:13.000ZCVSS 7.8

Was das Advisory beschreibt

In the Linux kernel, the following vulnerability has been resolved: bpf: Disable preemption in __bpf_get_stack get_perf_callchain() returns a per-CPU perf_callchain_entry buffer and releases its recursion slot via put_callchain_entry() before returning, so nothing keeps the entry reserved while __bpf_get_stack() consumes it below. A preemptible BPF program (e.g. a non-sleepable raw tracepoint program on a PREEMPT kernel, which runs under migrate_disable() but not preempt_disable()) can be scheduled out between obtaining the entry and the copy. Another task scheduled on the same CPU then reuses the same per-CPU buffer and overwrites trace->nr with a larger value. copy_len is then computed from the inflated trace->nr and can exceed the caller's buffer, causing an out-of-bounds write in the memcpy() and in the build_id path. The rcu_read_lock() taken here alone does not prevent this. It is only taken on the may_fault path, and under CONFIG_PREEMPT_RCU it does not disable preemption; it merely keeps perf's callchain buffer array alive (freed via call_rcu()) and does nothing to stop another task from reusing the entry. Disable preemption around obtaining the callchain entry and copying it into the caller's buffer, so the entry cannot be reused underneath us and trace->nr stays bounded by max_depth. Build ID resolution may fault and is therefore deferred until after preemption is re-enabled; by then the instruction pointers have already been copied into buf, so it operates only on that private copy. Note, preempt_disable() also subsumes the buffer-lifetime guarantee the rcu_read_lock() provided, since a preempt-disabled section is an RCU read-side critical section for the callchain buffers' call_rcu() reclaim. [ changed Fixes: commit ]

Quelle: EUVD (ENISA), im Wortlaut der Meldung.

Produkte, die das Advisory nennt

Diese Angaben stammen aus der Meldung selbst, nicht aus einer Prüfung durch uns.

• Linux — Linux c195651e565ae7f41a68acb7d4aa7390ad215de1 <b1a47b2708d4e95dbd23aee2ec83752190897b3f; c195651e565ae7f41a68acb7d4aa7390ad215de1 <8c5ba022f2085ea42d011497a6e92e527d123b9b; patch: 7.2.4; patch: 7.3-rc1; patch: 6.18.50; c195651e565ae7f41a68acb7d4aa7390ad215de1 <9a23747909fcae707990c8466c381a0e7acfaa4e; 4.18; patch: 0; patch: 6.12.109; c195651e565ae7f41a68acb7d4aa7390ad215de1 <dbfecc8a6631c0d3626c14ba1f1a485a4498445a

Die genannten Versionen sind die Angabe der Meldung. Patchlage vergleicht keine Versionsnummern und leitet aus ihnen keine Aussage ab — welche Version installiert ist, muss ein Mensch nachsehen.

Im Produktkatalog geführt

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• Linux — Linux

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