CVE-2026-89796

CVE CVE-2026-89796EUVD EUVD-2026-80396Veröffentlicht 2026-09-16T10:30:27.000ZZuletzt geändert 2026-09-21T13:15:02.000Z

Was das Advisory beschreibt

In the Linux kernel, the following vulnerability has been resolved: mm/damon/core: avoid infinite kdamond_merge_regions() internal loop Patch series "mm/damon: unurgent fixes for infinite loop, NULL de-ref and races", v1.1. Sashiko found a few issues in DAMON that could cause infinite loop, NULL dereference and monitoring results degradation. The first two sounds scary but the infinite loop happens only under unreasonable user setup. The NULL dereference is only in a unit test. Monitoring results degradation is trivial since it is only best-effort, and those happens from only unlikely races. Still those are bugs that better to fix if possible. Fix those. This patch (of 6): Due to online parameter update like events, the number of DAMON regions could be higher than the user-set upper limit. kdamond_merge_regions() repeats merge regions until the number meets the limit, while doubling the merge threshold up to the theoretical maximum threshold. It is tried only up to the theoretical maximum threshold because even the aggressive merging can fail from reducing the number of regions under the user-defined upper limit. For example, there could be many user-defined non-contiguous regions that cannot be merged. The threshold based loop break condition is evaluated by comparing the threshold for the next merging try against the theoretical maximum threshold. If max_thres is larger than UINT_MAX / 2, doubling the threshold could make it overflow, and bypass the loop break condition. In the case, if the number of regions cannot be reduced under the upper limit like explained above, the loop will run infinitely. Prevent the case by doing the break condition check before doubling the threshold. Also, prevent the threshold exceeding the maximum threshold, as it could overflow and apply the wrong merge threshold. This issue is unlikely to occur in real world, since having the max_thres higher than UINT_MAX / 2 require unrealistically large aggregation intervals compared to the sampling interval. Also, it requires an unrealistically large number of uncontiguous regions setup. Nonetheless, the consequence is bad and the fix is simple. The issue was discovered [1] by Sashiko.

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 310d6c15e9104c99d5d9d0ff8e5383a79da7d5e6 <50a7a5aec1aa43efc297fd4377c1cbdc7d15620d; 11078e2d11465518a9e85096bd28f8cd5fa1ea41; 310d6c15e9104c99d5d9d0ff8e5383a79da7d5e6 <123e4619ab6c8ab1c4cb1d7a58311a2af13929cd; patch: 7.3-rc1; patch: 0; 6.9.10 <6.10; f2bd3184b6aeca6a497394b558337246e09fc02d; patch: 7.2.5; 310d6c15e9104c99d5d9d0ff8e5383a79da7d5e6 <769c16699c89811386eb003c8fd9dcb8d405b316; d7eda72e59bbf3ed592db7ff0fd8c246c73149a8; 6.1.101 <6.2; 1e865019cef354a5f0314491b4b4fc9f9a613642; 310d6c15e9104c99d5d9d0ff8e5383a79da7d5e6 <8a96a06e04d210845be5d9581c0e9e338947e8f8; 6.6.41 <6.7; 5.15.164 <5.16; patch: 6.18.53; 6.10; patch: 6.12.111

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

Für diese Produkte kann ein Bestand in Patchlage erfasst werden. Ein Advisory dazu erscheint am Morgen danach im Lagebericht.

• Linux — Linux

Patchlage meldet Treffer und Verdachtsfälle. Zu allem anderen sagt dieses System nichts — weder diese Seite noch der Lagebericht behauptet je, dass ein Bestand sicher ist.