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CVE-2026-72135

Vulnérabilité élevée dans Linux (Linux)

CVSS 7.8 · Élevée
EPSS 0.2%
Linux•Linux•Versions : <=6.1.*, 7.1.5, 6.18.40, <=6.12.*, <f20d61c22bcaf172d6790b6500e3838e532e71c8, <9c513dabd4540f811585a2087f23069767a284da, 0, <dda695fab5e21f923d29e8cb01df256468ddfbd1, <21a13f932972bc9836f58c44fcd47c62abdecd95, <=7.1.*, <ada4b9a5087ea7f30dd8e4c6411a4fb6547eb1ed, <947b773caaa548672184df025271b29bdc80b0f1, 6.1.178, <ed0ffc2c016629e40ba041ed0424a772d8b02e2c, 9488585b21bef0df1217e510c7134905d1d376a7, <=5.10.*, <=6.6.*, 6.12.97, 5.0, <5.0, <=6.18.*, 5.15.212, 6.6.145, 5.10.261, <232dcf908eb7eb9d8046a9597975caf44270966e, <=*, <=5.15.*, 7.2

Description

In the Linux kernel, the following vulnerability has been resolved: tpm: Make the TPM character devices non-seekable The TPM character devices expose a sequential command/response interface, but their open handlers leave FMODE_PREAD and FMODE_PWRITE enabled. After a command leaves a response pending, pread(fd, buf, 16, 0x1400) passes 0x1400 as *off to tpm_common_read(). The transfer length is bounded by response_length, but the offset is used unchecked when forming data_buffer + *off. A sufficiently large offset therefore causes an out-of-bounds heap read through copy_to_user() and, if the copy succeeds, an out-of-bounds zero-write through the following memset(). Positional I/O does not provide coherent semantics for this interface. An arbitrary pread offset cannot represent how much of a response has been consumed sequentially. The write callback always stores a command at the start of data_buffer, while pwrite() does not update file->f_pos and can leave the sequential read cursor stale. Call nonseekable_open() from both open handlers. This removes FMODE_PREAD and FMODE_PWRITE, causing positional reads and writes to fail with -ESPIPE before reaching the TPM callbacks, and explicitly marks the files non-seekable. Normal read() and write() continue to use the existing sequential f_pos cursor, leaving the response state machine unchanged. Tested on Linux 6.12 with KASAN and a swtpm TPM2 device: - sequential partial reads returned the complete response - pread() and preadv() with offset 0x1400 returned -ESPIPE - pwrite() and pwritev() with offset zero returned -ESPIPE - the pending response remained intact after the rejected operations - a subsequent normal command/response cycle completed normally - no KASAN report was produced.

Gravité et risque d'exploitation

CVE-2026-72135 obtient un score CVSS de 7.8/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.17 %, ce qui la place devant 5.8 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, 7.1.5, 6.18.40, <=6.12.*, <f20d61c22bcaf172d6790b6500e3838e532e71c8, <9c513dabd4540f811585a2087f23069767a284da, 0, <dda695fab5e21f923d29e8cb01df256468ddfbd1, <21a13f932972bc9836f58c44fcd47c62abdecd95, <=7.1.*, <ada4b9a5087ea7f30dd8e4c6411a4fb6547eb1ed, <947b773caaa548672184df025271b29bdc80b0f1, 6.1.178, <ed0ffc2c016629e40ba041ed0424a772d8b02e2c, 9488585b21bef0df1217e510c7134905d1d376a7, <=5.10.*, <=6.6.*, 6.12.97, 5.0, <5.0, <=6.18.*, 5.15.212, 6.6.145, 5.10.261, <232dcf908eb7eb9d8046a9597975caf44270966e, <=*, <=5.15.*, 7.2) est présent sur votre parc.
  • Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
  • À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
  • Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.

Références

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