Look up another CVE · open CVE-2026-80737 in the interactive tracker
CVE-2026-80737
serial: amba-pl011: synchronize DMA teardown
Published 2026-09-03 (2 months ago) by the Linux kernel CNA. Subsystem drivers/tty. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-80737 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 | fixedDLA-4777-1 · 2026-09-08 · text | 6.1.187-1 | Update the kernel and reboot. DLA-4777-1 shipped the fix on 2026-09-08, in 6.1.187-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.107-1 | Update the kernel and reboot. Fixed in 6.12.107-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.1.9-1 | Update the kernel and reboot. Fixed in 7.1.9-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.9-1 | Update the kernel and reboot. Fixed in 7.1.9-1. A running kernel keeps the old code until the machine restarts. |
| Debian 12bookworm · linux-6.12 | fixedDLA-4788-1 · 2026-09-19 · text | 6.12.107-1~deb12u1 | Update the kernel and reboot. DLA-4788-1 shipped the fix on 2026-09-19, in 6.12.107-1~deb12u1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
dmaengine_terminate_all() does not wait for a running callback, so the TX callback can still touch the TX buffer after it is freed. The RX poll timer reads the RX buffers without the port lock. Switch to dmaengine_terminate_sync() and delete the RX timer before freeing the buffers.
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/tty/serial/amba-pl011.c
- What this is
- ARM PRIMECELL UART PL010 AND PL011 DRIVERSMAINTAINERS section matched on drivers/tty/serial/amba-pl01*.c · Odd Fixes
Check it on the machine
grep -w CONFIG_SERIAL_AMBA_PL011 /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 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.
- bookwormYnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, i386/686, i386/686-pae, i386/rt/686-pae, ppc64el/powerpc64le
- trixieYnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- forky, sidYnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt-amd64, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- bookworm · linux-6.12Ynot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k
- Y
- built in where it is built at all; some flavours do not build it
- Build switch
- CONFIG_SERIAL_AMBA_PL011
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
- 2026-09-03 (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
- 0.13%, higher than 2.3% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/tty
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 2.6.39 | 5.10.267 | a38fae9d212e |
| 2.6.39 | 5.15.218 | 44bd0ecc3444 |
| 2.6.39 | 6.1.185 | f70c9d4fba46 |
| 2.6.39 | 6.6.154 | c8c8e895f65f |
| 2.6.39 | 6.12.106 | 9f6989e477f0 |
| 2.6.39 | 6.18.45 | 5974cb66681e |
| 2.6.39 | 7.1.9 | fdfb46c38724 |
| 2.6.39 | 7.2 | 440915499231 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4788-1 | 2026-09-19 | bookworm 6.12.107-1~deb12u1 | tracker |
| DLA-4777-1 | 2026-09-08 | bookworm 6.1.187-1 | 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
- Local tty device access via open/write/close on /dev/ttyAMA* or similar; PL011 DMA teardown runs in pl011_shutdown from uart_close/hangup/suspend, not via network protocols.
- AC:LAttack complexity, low
- Attacker with tty fd controls DMA load (large writes for TX DMA, active RX) and teardown timing via close/hangup; they can repeatedly race shutdown against in-flight DMA callbacks/timers without uncontrollable conditions.
- PR:LPrivileges required, low
- Requires open/write/close on the UART tty node, typically granted via dialout group on embedded ARM systems with PL011 DMA; not via user namespaces alone, but no root required on auxiliary serial ports.
- UI:NUser interaction, none
- Attacker performs all steps themselves (open port, queue DMA traffic, close); no separate victim action needed.
- S:UScope, unchanged
- Kernel heap/coherent-buffer UAF during UART driver teardown affects only local kernel resources; no VM escape, IOMMU bypass, or cross-security-authority boundary.
- C:HConfidentiality impact, high
- TX DMA callback or RX poll timer can access freed TX kmalloc buffer or RX dma coherent pages, yielding UAF read primitives over kernel memory and potential information disclosure.
- I:HIntegrity impact, high
- Post-free access via pl011_dma_tx_refill/dma_map or pl011_dma_rx_poll writing into tty flip buffers enables heap corruption and potential kernel code execution or privilege escalation.
- A:HAvailability impact, high
- UAF during DMA teardown can provoke kernel oops/panic from concurrent access to freed buffers, and repeated triggering can deny UART service or crash the host.