CVE-2026-23085

NameCVE-2026-23085
DescriptionIn the Linux kernel, the following vulnerability has been resolved: irqchip/gic-v3-its: Avoid truncating memory addresses On 32-bit machines with CONFIG_ARM_LPAE, it is possible for lowmem allocations to be backed by addresses physical memory above the 32-bit address limit, as found while experimenting with larger VMSPLIT configurations. This caused the qemu virt model to crash in the GICv3 driver, which allocates the 'itt' object using GFP_KERNEL. Since all memory below the 4GB physical address limit is in ZONE_DMA in this configuration, kmalloc() defaults to higher addresses for ZONE_NORMAL, and the ITS driver stores the physical address in a 32-bit 'unsigned long' variable. Change the itt_addr variable to the correct phys_addr_t type instead, along with all other variables in this driver that hold a physical address. The gicv5 driver correctly uses u64 variables, while all other irqchip drivers don't call virt_to_phys or similar interfaces. It's expected that other device drivers have similar issues, but fixing this one is sufficient for booting a virtio based guest.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDLA-4475-1, DLA-4476-1, DSA-6126-1, DSA-6127-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
linux (PTS)bullseye5.10.223-1vulnerable
bullseye (security)5.10.249-1fixed
bookworm6.1.159-1vulnerable
bookworm (security)6.1.162-1fixed
trixie6.12.63-1vulnerable
trixie (security)6.12.73-1fixed
forky, sid6.18.12-1fixed
linux-6.1 (PTS)bullseye (security)6.1.162-1~deb11u1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
linuxsourcebullseye5.10.249-1DLA-4475-1
linuxsourcebookworm6.1.162-1DSA-6127-1
linuxsourcetrixie6.12.69-1DSA-6126-1
linuxsource(unstable)6.18.8-1
linux-6.1sourcebullseye6.1.162-1~deb11u1DLA-4476-1

Notes

https://git.kernel.org/linus/8d76a7d89c12d08382b66e2f21f20d0627d14859 (6.19-rc7)

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