# CVE-2026-23055: i2c: riic: Move suspend handling to NOIRQ phase > A kernel warning in the Renesas I2C driver during suspend can cause system instability or crashes, requiring a kernel patch. - **Severity:** Not scored - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 4 Feb 2026 - **Updated:** 11 May 2026 - **Also known as:** BELL-CVE-2026-23055, DEBIAN-CVE-2026-23055, GHSA-9pxj-wr74-v9rh, UBUNTU-CVE-2026-23055 ## What is CVE-2026-23055? CVE-2026-23055 is a denial of service vulnerability in Linux, published on 4 Feb 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: riic: Move suspend handling to NOIRQ phase Commit 53326135d0e0 ("i2c: riic: Add suspend/resume support") added suspend support for the Renesas I2C driver and following this change on RZ/G3E the following WARNING is seen on entering suspend ... [ 134.275704] Freezing remaining freezable tasks completed (elapsed 0.001 seconds) [ 134.285536] ------------[ cut here ]------------ [ 134.290298] i2c i2c-2: Transfer while suspended [ 134.295174] WARNING: drivers/i2c/i2c-core.h:56 at __i2c_smbus_xfer+0x1e4/0x214, CPU#0: systemd-sleep/388 [ 134.365507] Tainted: [W]=WARN [ 134.368485] Hardware name: Renesas SMARC EVK version 2 based on r9a09g047e57 (DT) [ 134.375961] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 134.382935] pc : __i2c_smbus_xfer+0x1e4/0x214 [ 134.387329] lr : __i2c_smbus_xfer+0x1e4/0x214 [ 134.391717] sp : ffff800083f23860 [ 134.395040] x29: ffff800083f23860 x28: 0000000000000000 x27: ffff800082ed5d60 [ 134.402226] x26: 0000001f4395fd74 x25: 0000000000000007 x24: 0000000000000001 [ 134.409408] x23: 0000000000000000 x22: 000000000000006f x21: ffff800083f23936 [ 134.416589] x20: ffff0000c090e140 x19: ffff0000c090e0d0 x18: 0000000000000006 [ 134.423771] x17: 6f63657320313030 x16: 2e30206465737061 x15: ffff800083f23280 [ 134.430953] x14: 0000000000000000 x13: ffff800082b16ce8 x12: 0000000000000f09 [ 134.438134] x11: 0000000000000503 x10: ffff800082b6ece8 x9 : ffff800082b16ce8 [ 134.445315] x8 : 00000000ffffefff x7 : ffff800082b6ece8 x6 : 80000000fffff000 [ 134.452495] x5 : 0000000000000504 x4 : 0000000000000000 x3 : 0000000000000000 [ 134.459672] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0000c9ee9e80 [ 134.466851] Call trace: [ 134.469311] __i2c_smbus_xfer+0x1e4/0x214 (P) [ 134.473715] i2c_smbus_xfer+0xbc/0x120 [ 134.477507] i2c_smbus_read_byte_data+0x4c/0x84 [ 134.482077] isl1208_i2c_read_time+0x44/0x178 [rtc_isl1208] [ 134.487703] isl1208_rtc_read_time+0x14/0x20 [rtc_isl1208] [ 134.493226] __rtc_read_time+0x44/0x88 [ 134.497012] rtc_read_time+0x3c/0x68 [ 134.500622] rtc_suspend+0x9c/0x170 The warning is triggered because I2C transfers can still be attempted while the controller is already suspended, due to inappropriate ordering of the system sleep callbacks. If the controller is autosuspended, there is no way to wake it up once runtime PM disabled (in suspend_late()). During system resume, the I2C controller will be available only after runtime PM is re-enabled (in resume_early()). However, this may be too late for some devices. Wake up the controller in the suspend() callback while runtime PM is still enabled. The I2C controller will remain available until the suspend_noirq() callback (pm_runtime_force_suspend()) is called. During resume, the I2C controller can be restored by the resume_noirq() callback (pm_runtime_force_resume()). Finally, the resume() callback re-enables autosuspend. As a result, the I2C controller can remain available until the system enters suspend_noirq() and from resume_noirq(). ## Which versions are affected by CVE-2026-23055? ## How do I fix CVE-2026-23055? Apply the vendor's patch. ## Is CVE-2026-23055 being exploited? There is no known exploitation of CVE-2026-23055 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-23055 and fix it if it is affected. What it is: CVE-2026-23055 is a denial of service vulnerability in Linux, published on 4 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-23055 in the wild and no public exploit code. Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-23055/ (Markdown: https://insights.sbomify.com/CVE-2026-23055/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23055 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23055 - OSV: https://osv.dev/vulnerability/CVE-2026-23055 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-23055/ Summaries are generated and may contain mistakes; the official description above is the record.