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CVE-2026-72485
coresight: platform: defer connection counter increment until alloc succeeds
Published 2026-08-15 (2 months ago) by the Linux kernel CNA. Subsystem drivers/hwtracing. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-72485 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | not affected | 6.1.190-1 | Nothing to do. bookworm never shipped the vulnerable code. |
| Debian 13trixie | fixedDSA-6528-1 · 2026-09-29 · text | 6.12.111-1 | Update the kernel and reboot. DSA-6528-1 shipped the fix on 2026-09-29, in 6.12.111-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
| Debian 12bookworm · linux-6.12 | fixedDLA-4817-1 · 2026-10-04 · text | 6.12.111-1~deb12u1 | Update the kernel and reboot. DLA-4817-1 shipped the fix on 2026-10-04, in 6.12.111-1~deb12u1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
coresight_add_out_conn() increments nr_outconns before calling devm_krealloc_array() and again before devm_kmalloc(). If either allocation fails, the counter is already bumped while the corresponding array entry is NULL or uninitialized garbage. coresight_add_in_conn() has the same problem with nr_inconns and devm_krealloc_array(). In both cases the probe returns -ENOMEM, which causes coresight_get_platform_data() to call coresight_release_platform_data() for cleanup. That function iterates up to nr_outconns (or nr_inconns) entries and dereferences each pointer unconditionally, hitting the NULL or garbage entry and panicking instead of failing gracefully. Fix by moving the counter increments to after all allocations succeed, so the struct is always consistent on any error path.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
drivers/hwtracing/coresight/coresight-platform.c
- What this is
- ARM/CORESIGHT FRAMEWORK AND DRIVERSMAINTAINERS section matched on drivers/hwtracing/coresight/* · coresight@lists.linaro.org · Maintained
- Kernel module
- coresight
Check it on the machine
grep -w CONFIG_CORESIGHT /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
lsmod | grep -w coresightPrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.
- bookwormMnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, i386/686, i386/686-pae, i386/rt/686-pae, ppc64el/powerpc64le
- trixieMnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, armel/rpi, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- forky, sidMnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt-amd64, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- bookworm · linux-6.12Mnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k
- M
- a module where it is built at all; some flavours do not build it
- Build switch
- CONFIG_CORESIGHT
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-08-15 (2 months ago)source
- CVSS
- 7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.17%, higher than 5.7% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- drivers/hwtracing
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.5 | 6.6.158 | dd3c9e1c9858 |
| 6.5 | 6.12.111 | aed6915c2f30 |
| 6.5 | 6.18.53 | 09c44549820d |
| 6.5 | 7.1.5 | 8ca9adc80588 |
| 6.5 | 7.2 | 1563ae33dc4f |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4817-1 | 2026-10-04 | bookworm 6.12.111-1~deb12u1 | tracker |
| DSA-6528-1 | 2026-09-29 | trixie 6.12.111-1 | tracker |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:LAttack vector, local
- The flaw is in ARM CoreSight platform driver probe (coresight_get_platform_data/coresight_add_out_conn) while parsing firmware DT/ACPI connection graphs during local device initialization; there is no network, Bluetooth, or physical-bus path to this code.
- AC:LAttack complexity, low
- An attacker can reliably force devm_kmalloc/devm_krealloc failure via memory exhaustion and time it with deferred CoreSight probe retries; success does not depend on uncontrollable layout or victim state beyond attacker-driven memory pressure.
- PR:LPrivileges required, low
- Only a local unprivileged process is needed to exhaust memory; CoreSight drivers commonly reprobe after -EPROBE_DEFER once dependencies appear, so no init-namespace root, CAP_SYS_MODULE, or CAP_NET_ADMIN is required to reach the failing cleanup path.
- UI:NUser interaction, none
- No victim interaction is required; the attacker alone can create memory pressure and rely on automatic deferred driver reprobe without anyone mounting devices, opening files, or clicking prompts.
- S:UScope, unchanged
- Impact is a kernel panic and in-kernel memory corruption within the same kernel security authority; CoreSight is an on-chip trace/debug subsystem and this is not a VM escape, IOMMU bypass, or sandbox boundary crossing.
- C:HConfidentiality impact, high
- If krealloc succeeds but the connection kmalloc fails, nr_outconns is already inflated while out_conns contains an uninitialized garbage pointer; coresight_release_platform_data() unconditionally dereferences conns[i]->dest_fwnode, enabling arbitrary kernel memory reads before panic.
- I:HIntegrity impact, high
- Error cleanup calls fwnode_handle_put() and devm_kfree() on NULL or garbage connection pointers, corrupting kernel refcount/heap metadata and creating exploitable write primitives beyond a benign NULL dereference crash.
- A:HAvailability impact, high
- The inconsistent nr_outconns counter makes coresight_release_platform_data() dereference NULL or garbage entries during probe error cleanup, causing a kernel oops/panic and total system unavailability on affected ARM/ARM64 platforms (phones, embedded, automotive, cloud).