CVE-2026-52948 i2c: dev: prevent integer overflow in I2C_TIMEOUT ioctl

What is CVE-2026-52948?

CVE-2026-52948 is a medium-severity vulnerability in Linux kernel, published on 24 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

i2c: dev: prevent integer overflow in I2C_TIMEOUT ioctl

While fuzzing with Syzkaller, a persistent `schedule_timeout: wrong timeout value` warning was observed, accompanied by SMBus controller state machine corruption.

The I2C_TIMEOUT ioctl accepts a user-provided timeout in multiples of 10 ms. The user argument is checked against INT_MAX, but it is subsequently multiplied by 10 before being passed to msecs_to_jiffies().

A malicious user can pass a large value (e.g., 429496729) that passes the `arg > INT_MAX` check but overflows when multiplied by 10. This results in a truncated 32-bit unsigned value that bypasses the internal `(int)m < 0` check in `msecs_to_jiffies()`.

The truncated value is then assigned to `client->adapter->timeout` (a signed 32-bit int), which is reinterpreted as a negative number. When passed to wait_for_completion_timeout(), this negative value undergoes sign extension to a 64-bit unsigned long, triggering the `schedule_timeout` warning and causing premature returns. This leaves the SMBus state machine in an unrecoverable state, constituting a local Denial of Service (DoS).

Fix this by bounding the user argument to `INT_MAX / 10`.

[wsa: move the comment as well]

Weakness: CWE-190

Which versions are affected by CVE-2026-52948?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-52948?

Apply the vendor's patch.

Is CVE-2026-52948 being exploited?

There is no known exploitation of CVE-2026-52948 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-90513, BELL-CVE-2026-52948, DEBIAN-CVE-2026-52948, GHSA-rj5f-9xf7-69h7, ROOT-OS-DEBIAN-11-CVE-2026-52948, ROOT-OS-DEBIAN-12-CVE-2026-52948 and 3 more.