CVE-2026-64294

CVE CVE-2026-64294EUVD EUVD-2026-49006Veröffentlicht 2026-07-25T08:49:32.000Z

Was das Advisory beschreibt

In the Linux kernel, the following vulnerability has been resolved: mm: do file ownership checks with the proper mount idmap Ever since idmapped mounts were introduced, inode ownership checks (for side-channel protection) in mincore() and madvise(MADV_PAGEOUT) were done against the nop_mnt_idmap, which completely ignores the file's mount's idmap. This results in odd edgecases like: 1) mount/bind-mount with an idmap userA:userB:1 2) userB runs an owner_or_capable() check on file that is owned by userA on-disk/in-memory, but owned by userB after idmap translation 3) owner_or_capable() mysteriously fails as the correct idmap wasn't supplied In the case of mincore/madvise MADV_PAGEOUT, this is usually benign, because file_permission(file, MAY_WRITE) will probably succeed, as it uses the proper idmap internally, but it does not need to be the case on e.g a 0444 file where even the owner itself doesn't have permissions to write to it. Since this is clearly not trivial to get right, introduce a file_owner_or_capable() that can carry the correct semantics, and switch the various users in mm to it. The issue was found by manual code inspection & an off-list discussion with Jan Kara.

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 patch: 6.6.145; patch: 7.2-rc3; 9caccd41541a6f7d6279928d9f971f6642c361af <5c942ad7df75925ee166e7f0fb36892d8dde376b; patch: 6.18.39; 9caccd41541a6f7d6279928d9f971f6642c361af <04ba248d02d9eaa3d9077b00a6134caa75fa3e90; 5.12; 9caccd41541a6f7d6279928d9f971f6642c361af <8344bdf0629457e532797b42d9d2bbf2a2900bbf; patch: 7.1.4; patch: 0; 9caccd41541a6f7d6279928d9f971f6642c361af <e187bc02f8fa4226d62814592cf064ee4557c470; patch: 6.12.96; 9caccd41541a6f7d6279928d9f971f6642c361af <744b23aa430d52f5c8e4dbff7d71496d6643bed2

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.