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CVE-2026-64191

Vulnérabilité élevée dans Linux (Linux)

CVSS 7.8 · Élevée
EPSS 0.1%
Linux•Linux•Versions : <=6.1.*, <=7.0.*, <=6.12.*, 6.6.144, 5.15.211, 7.0.14, <6036b5067a8199ba7a2dc7b377d4b9dd276d5f9e, 4710317891e4824ce1510a6b5066abbd3e917750, 0, <21e87f336ac6303fed54a69b1d0d79a23b25c8d0, 5.10.260, <4bd8635f28c135a08aac6badcd7d9b5cdb34335f, <7e9072dbd5f2f17934751873450d2c22080ead80, <=5.10.*, <=6.6.*, 6.12.95, <5f4d2bd028ebb6e4c09a9d64842546022321d4a7, <0526931b16e5a118d367b7bfce7d797e63f7ac69, <3fd225f3e4cd67ec8ddab1afed9da03c7c43537c, <2.6.33, <1c4ffe6b4f04365485ed58d64c9bb86b46fc9037, 6.18.37, 2.6.33, 7.1, <=6.18.*, 6.1.177, <=*, <=5.15.*

Description

In the Linux kernel, the following vulnerability has been resolved: i2c: stub: Reject I2C block transfers with invalid length The I2C_SMBUS_I2C_BLOCK_DATA case in stub_xfer() uses data->block[0] as the transfer length. The existing check only clamps it to avoid overrunning the chip->words[256] register array, but does not validate it against I2C_SMBUS_BLOCK_MAX (32), which is the limit of the union i2c_smbus_data.block buffer (34 bytes total). The driver is a development/test tool (CONFIG_I2C_STUB=m, not built by default) that must be loaded with a chip_addr= parameter. A local user with access to /dev/i2c-* can issue an I2C_SMBUS ioctl with I2C_SMBUS_I2C_BLOCK_DATA and data->block[0] > 32, causing stub_xfer() to read or write past the end of the union i2c_smbus_data.block buffer: BUG: KASAN: stack-out-of-bounds in stub_xfer (drivers/i2c/i2c-stub.c:223) Read of size 1 at addr ffff88800abcfd92 by task exploit/81 Call Trace: <TASK> stub_xfer (drivers/i2c/i2c-stub.c:223) __i2c_smbus_xfer (drivers/i2c/i2c-core-smbus.c:593) i2c_smbus_xfer (drivers/i2c/i2c-core-smbus.c:536) i2cdev_ioctl_smbus (drivers/i2c/i2c-dev.c:391) i2cdev_ioctl (drivers/i2c/i2c-dev.c:478) __x64_sys_ioctl (fs/ioctl.c:583) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) </TASK> The bug exists because i2c-stub implements .smbus_xfer directly, bypassing the I2C_SMBUS_BLOCK_MAX validation in i2c_smbus_xfer_emulated(). The I2C_SMBUS_BLOCK_DATA case in the same function correctly validates against I2C_SMBUS_BLOCK_MAX, but the I2C_SMBUS_I2C_BLOCK_DATA case does not. Fix by rejecting transfers with data->block[0] == 0 or data->block[0] > I2C_SMBUS_BLOCK_MAX with -EINVAL, consistent with both the I2C_SMBUS_BLOCK_DATA case in the same function and the I2C_SMBUS_I2C_BLOCK_DATA validation in i2c_smbus_xfer_emulated().

Gravité et risque d'exploitation

CVE-2026-64191 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 0.13 %, ce qui la place devant 2.1 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, <=7.0.*, <=6.12.*, 6.6.144, 5.15.211, 7.0.14, <6036b5067a8199ba7a2dc7b377d4b9dd276d5f9e, 4710317891e4824ce1510a6b5066abbd3e917750, 0, <21e87f336ac6303fed54a69b1d0d79a23b25c8d0, 5.10.260, <4bd8635f28c135a08aac6badcd7d9b5cdb34335f, <7e9072dbd5f2f17934751873450d2c22080ead80, <=5.10.*, <=6.6.*, 6.12.95, <5f4d2bd028ebb6e4c09a9d64842546022321d4a7, <0526931b16e5a118d367b7bfce7d797e63f7ac69, <3fd225f3e4cd67ec8ddab1afed9da03c7c43537c, <2.6.33, <1c4ffe6b4f04365485ed58d64c9bb86b46fc9037, 6.18.37, 2.6.33, 7.1, <=6.18.*, 6.1.177, <=*, <=5.15.*) 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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