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CVE-2026-80645
rapidio/tsi721: prevent a bad dereference in tsi721_db_dpc()
Published 2026-08-28 (2 months ago) by the Linux kernel CNA. Subsystem drivers/rapidio. Debian urgency: not yet assigned.
Debian does not build this code. The per-release build detail is under "Where it lives" below.
What to do, per Debian release
Debian's own status for CVE-2026-80645 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 | fixed | 6.1.180-1 | Update the kernel and reboot. Fixed in 6.1.180-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.100-1 | Update the kernel and reboot. Fixed in 6.12.100-1. 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. |
The vulnerability
What the bug is
With a list_for_each() loop, if we don't find the item we are looking for in the list, then the loop exits with the iterator, which is "dbell" in this loop, pointing to invalid memory. This code uses the "found" variable to determine if we have found the doorbell we are looking for or not. However, the problem that the "found" variable needs to be set to false at the start of each iteration, otherwise after the first correct doorbell, then everything is marked as found. Reset the "found" to false at the start of the iteration and move the variable inside the loop.
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/rapidio/devices/tsi721.c
- What this is
- RAPIDIO SUBSYSTEMMAINTAINERS section matched on drivers/rapidio/ · Maintained
- Kernel module
- none to look for. The file would have gone into tsi721_mport, and Debian does not compile it into that module, so finding tsi721_mport in lsmod would say nothing about this CVE.
Check it on the machine
grep -wE 'CONFIG_RAPIDIO|CONFIG_RAPIDIO_TSI721' /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.
Show whether Debian builds this, per release
Debian does not build this code. In 4 releases below, every kernel flavour Debian publishes has the switch off, so the vulnerable file is compiled into no kernel binary Debian ships.
- bookworm, trixie, forky, sidn
- n
- not enabled on any flavour - this release does not build the code
- Build switches
- CONFIG_RAPIDIO, CONFIG_RAPIDIO_TSI721
- Reads as
- all on means the file is compiled; any one off means it is not.
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
- 2026-08-28 (2 months ago)source
- CVSS
- 8.1 high
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Hsource recompute it - Attack vector
- adjacent network (AV:A)source
- EPSS
- 0.40%, higher than 32.9% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/rapidio
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 3.2 | 5.10.261 | 9e775c319990 |
| 3.2 | 5.15.212 | 81c06ef66c3a |
| 3.2 | 6.1.178 | 13092966ba5d |
| 3.2 | 6.6.145 | acd54f42abbb |
| 3.2 | 6.12.97 | 3b5c66e922aa |
| 3.2 | 6.18.40 | 070f356ea4f4 |
| 3.2 | 7.1.5 | dc28a14f3e45 |
| 3.2 | 7.2 | fc15e3a30ddd |
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:AAttack vector, adjacent network
- The bug is reached when inbound RapidIO doorbell packets are received by the TSI721 hardware, queued, and processed in tsi721_db_dpc() via tsi721_irqhandler()->tsi721_dbell_handler()->schedule_work(); any peer on the same SRIO fabric can send these unauthenticated doorbells without local OS access.
- AC:LAttack complexity, low
- On affected systems an attacker who can emit RapidIO doorbells can reliably trigger the flaw by sending a matching doorbell (e.g. rionet JOIN 0x1000) followed by a non-matching one in the same inbound queue; the stale found flag makes this deterministic, not race-dependent.
- PR:NPrivileges required, none
- Exploitation requires no Linux credentials on the victim host; inbound doorbells are accepted from remote fabric endpoints with no authentication, and the vulnerable workqueue path has no capability or permission checks beyond having the TSI721 driver loaded.
- UI:NUser interaction, none
- No victim interaction is required; the crash is triggered automatically when the hardware receives and the kernel processes the attacker-crafted doorbell sequence.
- S:UScope, unchanged
- Impact is confined to kernel memory and execution on the host running the TSI721 driver; it does not cross a VM, container, or IOMMU security boundary.
- C:NConfidentiality impact, none
- The failure mode is a bad pointer dereference/type confusion leading to an invalid indirect call through a mis-cast list head, not an attacker-controlled arbitrary kernel memory read or information disclosure primitive.
- I:HIntegrity impact, high
- When found is stale, dbell points at the mport->dbells list head cast to struct rio_dbell, and the kernel invokes dbell->dinb with attacker-controlled doorbell fields; this type confusion can corrupt kernel state or hijack control flow beyond a simple denial of service.
- A:HAvailability impact, high
- Invoking a mis-resolved function pointer from the list-head confusion causes a kernel oops/panic in interrupt-deferred workqueue context, crashing or hanging the entire system.