What’s Vulnerable › Vulnerabilities

CVE-2024-26844: block: Fix WARNING in _copy_from_iter

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2024-04-17 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: block: Fix WARNING in _copy_from_iter Syzkaller reports a warning in _copy_from_iter because an iov_iter is supposedly used in the wrong direction. The reason is that syzcaller managed to generate a request with a transfer direction of SG_DXFER_TO_FROM_DEV. This instructs the kernel to copy user buffers into the kernel, read into the copied buffers and then copy the data back to user space. Thus the iovec is used in both directions. Detect this situation in the block layer and construct a new iterator with the correct direction for the copy-in.

Affected products

• Linux kernel: before 6.1.80; from 6.2 before 6.6.19; from 6.7 before 6.7.7; 6.8-rc1 — fixed in 6.1.80, 6.6.19, 6.7.7

How to fix

Upgrade to a fixed version: Linux kernel 6.1.80, 6.6.19, 6.7.7. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/0f1bae071de9967602807472921829a54b2e5956
• https://git.kernel.org/stable/c/13f3956eb5681a4045a8dfdef48df5dc4d9f58a6
• https://git.kernel.org/stable/c/8fc80874103a5c20aebdc2401361aa01c817f75b
• https://git.kernel.org/stable/c/cbaf9be337f7da25742acfce325119e3395b1f1b
• https://git.kernel.org/stable/c/0f1bae071de9967602807472921829a54b2e5956
• https://git.kernel.org/stable/c/13f3956eb5681a4045a8dfdef48df5dc4d9f58a6
• https://git.kernel.org/stable/c/8fc80874103a5c20aebdc2401361aa01c817f75b
• https://git.kernel.org/stable/c/cbaf9be337f7da25742acfce325119e3395b1f1b

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