CVE-2026-52948

Summary

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]

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/e9ffd5f5050fbb199d270a85614cd27ebed6fbac
• https://git.kernel.org/stable/c/0b88ecfbc9dc33b4db8836c37b50cf174e6c0691
• https://git.kernel.org/stable/c/943e318eedbeaeea08ece3f5dd44c982f4ed2ef5
• https://git.kernel.org/stable/c/aa6ef734016912653a909477fb30aeb66c98b3a2
• https://git.kernel.org/stable/c/ff02add34ffd03449b8115904ebe2ec4fed022d4
• https://git.kernel.org/stable/c/ffbcf31f032eb454ebfd29309f51366fe57f4ac4
• https://git.kernel.org/stable/c/4576621dc6577f21a032acfd16c3ad61907a5ea7
• https://git.kernel.org/stable/c/617eb7c0961a8dfcfc811844a6396e406b2923ea

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