CVE-2026-23055: Linux kernel · i2c: riic: Move suspend handling to NOIRQ phase
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 6.17.0-1021.21~24.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:05 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.17.0-1021.21~24.04.1, 6.17.0-1021.24~24.04.1, 6.17.0-41.41~24.04.1 +3
Exploitation evidence
Disclosed: evidence found.
CVE published 4 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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().
References
- ubuntu.com/security/CVE-2026-23055 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-23055 (opens in a new tab)
- git.kernel.org/linus/e383f0961422f983451ac4dd6aed1a3d3311f2be (opens in a new tab)
- git.kernel.org/stable/c/0b4c0fbbe00b7de76bdaea7fa771017d7a979b0d (opens in a new tab)
- git.kernel.org/stable/c/469f8fe4c87e43520f279e45b927c35d6fe99194 (opens in a new tab)
- git.kernel.org/stable/c/e383f0961422f983451ac4dd6aed1a3d3311f2be (opens in a new tab)
- ubuntu.com/security/notices/USN-8570-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8594-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8604-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8605-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8570-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8669-1 (opens in a new tab)