CVE-2026-90200

CVE CVE-2026-90200EUVD EUVD-2026-81793Veröffentlicht 2026-09-17T16:07:18.000Z

Was das Advisory beschreibt

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: fix integer overflow in MFT cluster validation In ntfs_init_from_boot(), the boot sector's MFT cluster numbers are validated against the volume size with: if (mlcn * sct_per_clst >= sectors || mlcn2 * sct_per_clst >= sectors) goto out; mlcn and mlcn2 are u64 fields read directly from the boot sector. sct_per_clst is bounded above by 4096 (true_sectors_per_clst() plus the is_power_of_2() check below it), but the multiplication is done in u64 and wraps when mlcn (or mlcn2) is large enough -- e.g. mlcn near 2^62 with sct_per_clst == 4 wraps to 0, which compares below any non-zero 'sectors', so the check is bypassed and the malformed record is accepted. The accepted mlcn is then used unchanged in sbi->mft.lbo = mlcn << cluster_bits; In practice the resulting reads fail at the block layer (sb_bread() returns NULL via grow_buffers()'s check_mul_overflow() guard), so today this manifests as mount failing in odd places rather than as something more dangerous, but the validation step is still wrong and there is no reason for callers to rely on the block layer to catch a value that should never have been accepted in the first place. Use check_mul_overflow() to compute the two sector positions and fail the mount if either multiplication wraps; this preserves the existing semantics (mlcn * sct_per_clst >= sectors) instead of switching to division (mlcn >= sectors / sct_per_clst), which would tighten the check at edge cases where 'sectors' is not a multiple of sct_per_clst. The check_*_overflow() style is the one ntfs3 already uses for similar on-disk arithmetic in fs/ntfs3/run.c.

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: 7.3-rc1; 5.15; 82cae269cfa953032fbb8980a7d554d60fb00b17 <c510c63873103a5da6a498fe537bdb5d6f8d03a2; patch: 7.2.6; patch: 0; 82cae269cfa953032fbb8980a7d554d60fb00b17 <805cc5554b13d045dce9b03c13eaf015418739fd; patch: 6.18.52; patch: 6.12.110; patch: 6.6.157; 82cae269cfa953032fbb8980a7d554d60fb00b17 <f77a8d9fdf58e298b36564a44c27fadc617bdd28; 82cae269cfa953032fbb8980a7d554d60fb00b17 <dc6d85de7e2656e56e10ff5ba514f2583a4f612b; 82cae269cfa953032fbb8980a7d554d60fb00b17 <169383d8914b8fe03464a83540b5b6de3e7831af

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.