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Vulnerability · Published Apr 22, 2026 · Assigned by Linux

CVE-2026-31457mm/damon/sysfs: check contexts->nr in repeat_call_fn

Medium 5.5

In plain English

A medium-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.1%top 98.1% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: mm/damon/sysfs: check contexts->nr in repeat_call_fn damon_sysfs_repeat_call_fn() calls damon_sysfs_upd_tuned_intervals(), damon_sysfs_upd_schemes_stats(), and damon_sysfs_upd_schemes_effective_quotas() without checking contexts->nr. If nr_contexts is set to 0 via sysfs while DAMON is running, these functions dereference contexts_arr[0] and cause a NULL pointer dereference. Add the missing check. For example, the issue can be reproduced using DAMON sysfs interface and DAMON user-space tool (damo) [1] like below. $ sudo damo start --refresh_interval 1s $ echo 0 | sudo tee \ /sys/kernel/mm/damon/admin/kdamonds/0/contexts/nr_contexts

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:14linux6.19.11-1DEBIAN-CVE-2026-31457
Ubuntu:25.10linuxno fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-31457
Ubuntu:25.10linux-awsno fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-31457
Ubuntu:25.10linux-azureno fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-31457
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-31457
Ubuntu:25.10linux-gcpno fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-31457
Ubuntu:25.10linux-oracleno fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-31457
Ubuntu:25.10linux-raspino fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-31457
Ubuntu:25.10linux-realtimeno fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-31457
Ubuntu:25.10linux-riscvno fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-31457
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-31457
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-31457

Affected products (as reported)

VendorProductVersions
Linux Linux d809a7c64ba8229286b333c0cba03b1cdfb50238 – before 3527e9fdc38570cea0f6ddb7a2c9303d4044b217d809a7c64ba8229286b333c0cba03b1cdfb50238 – before 652cd0641a763dd0e846b0d12814977fadb2b7d8d809a7c64ba8229286b333c0cba03b1cdfb50238 – before 6557004a8b59c7701e695f02be03c7e20ed1cc15
Linux Linux 6.17

References