CVE-2023-52791: i2c: core: Run atomic i2c xfer when !preemptible

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: 2024-05-21 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: i2c: core: Run atomic i2c xfer when !preemptible Since bae1d3a05a8b, i2c transfers are non-atomic if preemption is disabled. However, non-atomic i2c transfers require preemption (e.g. in wait_for_completion() while waiting for the DMA). panic() calls preempt_disable_notrace() before calling emergency_restart(). Therefore, if an i2c device is used for the restart, the xfer should be atomic. This avoids warnings like: [ 12.667612] WARNING: CPU: 1 PID: 1 at kernel/rcu/tree_plugin.h:318 rcu_note_context_switch+0x33c/0x6b0 [ 12.676926] Voluntary context switch within RCU read-side critical section! ... [ 12.742376] schedule_timeout from wait_for_completion_timeout+0x90/0x114 [ 12.749179] wait_for_completion_timeout from tegra_i2c_wait_completion+0x40/0x70 ... [ 12.994527] atomic_notifier_call_chain from machine_restart+0x34/0x58 [ 13.001050] machine_restart from panic+0x2a8/0x32c Use !preemptible() instead, which is basically the same check as pre-v5.2.

Affected products

Linux kernel: from 5.2 before 5.4.262; from 5.5 before 5.10.202; from 5.11 before 5.15.140; from 5.16 before 6.1.64; from 6.2 before 6.5.13; from 6.6 before 6.6.3 — fixed in 5.10.202, 5.15.140, 5.4.262, 6.1.64, 6.5.13, 6.6.3

How to fix

Upgrade to a fixed version: Linux kernel 5.10.202, 5.15.140, 5.4.262, 6.1.64. Check the vendor advisory for mitigations.

References

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