Look up another CVE · open CVE-2026-89854 in the interactive tracker
CVE-2026-89854
scsi: qla2xxx: Fix cs84xx use-after-free on host teardown
Published 2026-09-16 (33 days ago) by the Linux kernel CNA. Subsystem drivers/scsi. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-89854 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-4841-1 · 2026-10-17 · text | 6.1.190-1 | Update the kernel and reboot. DLA-4841-1 shipped the fix on 2026-10-17, in 6.1.190-1. A running kernel keeps the old code until the machine restarts. |
| 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 | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. 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
qla84xx_put_chip() drops the last reference to ha->cs84xx and frees it via __qla84xx_chip_release() without clearing ha->cs84xx. During teardown it ran before scsi_remove_host(), which is what removes the 84xx_fw_version host sysfs attribute. A concurrent read of that attribute in the window between the two calls executes qla24xx_84xx_fw_version_show(), which dereferences the freed ha->cs84xx, resulting in a use-after-free. Move qla84xx_put_chip() to after scsi_remove_host() in both qla2x00_remove_one() and qla2x00_disable_board_on_pci_error(). Once scsi_remove_host() returns, the sysfs attribute is gone and kernfs has drained any in-flight show(), so no reader can touch cs84xx; the put still runs before the host and ha are freed.
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/scsi/qla2xxx/qla_os.c
- What this is
- QLOGIC QLA2XXX FC-SCSI DRIVERMAINTAINERS section matched on drivers/scsi/qla2xxx/ · linux-scsi@vger.kernel.org · Supported
- Kernel module
- qla2xxx
Check it on the machine
grep -w CONFIG_SCSI_QLA_FC /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 qla2xxxPrints 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/cloud-amd64, arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp
- trixieMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armel/rpi, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, s390x/s390x
- forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, s390x/s390x
- bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp
- M
- a module where it is built at all; some flavours do not build it
- Build switch
- CONFIG_SCSI_QLA_FC
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
- 2026-09-16 (33 days 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
- 0.16%, higher than 4.7% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/scsi
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 3.14 | 5.10.270 | 8c1ebcade6aa |
| 3.14 | 5.15.221 | 1d8bbc4344b9 |
| 3.14 | 6.1.188 | 2c3b17ee53f0 |
| 3.14 | 6.6.157 | ae09260be745 |
| 3.14 | 6.12.110 | fcf0804dfe05 |
| 3.14 | 6.18.51 | 8286a9095fb5 |
| 3.14 | 7.2.5 | 122bf170c94a |
| 3.14 | 7.3 | 33d102102d92 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4841-1 | 2026-10-17 | bookworm 6.1.190-1 | tracker |
| 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 UAF is reached from qla24xx_84xx_fw_version_show() on the SCSI host sysfs attribute while qla2x00_remove_one() tears down a QLogic ISP8432 (84xx) HBA. That is a local sysfs/PCI-unbind path, not a network or Fibre Channel frame handler.
- AC:LAttack complexity, low
- An attacker can loop-read /sys/class/scsi_host/hostN/84xx_fw_version while teardown runs. qla84xx_put_chip() freed cs84xx before scsi_remove_host(), leaving a large window through timer stop, DMA free, workqueue destroy, and fc_remove_host(). The attacker controls the sysfs side and can retry.
- PR:LPrivileges required, low
- 84xx_fw_version is DEVICE_ATTR(..., S_IRUGO) with no capable() check in qla24xx_84xx_fw_version_show(), so an unprivileged local user can read it. Per CNA driver-removal UAF precedent, concurrent PCI unbind or rmmod does not require the attacker to hold init-namespace root.
- UI:NUser interaction, none
- The attacker performs their own sysfs reads against 84xx_fw_version and can race routine driver unbind, rmmod, or PCI hot-remove. No separate victim action such as mounting a filesystem or confirming a prompt is required.
- S:UScope, unchanged
- The use-after-free corrupts the host kernel heap object qla_chip_state_84xx within the same kernel security authority. It is not a VM escape, IOMMU/DMA isolation bypass, or sandbox breakout.
- C:HConfidentiality impact, high
- qla84xx_put_chip() kfree()s ha->cs84xx without clearing the pointer; a concurrent show() dereferences ha->cs84xx->op_fw_version. This kernel heap UAF lets a reused object be read, enabling arbitrary kernel information disclosure.
- I:HIntegrity impact, high
- If the reused object's op_fw_version is zero, show() calls qla84xx_verify_chip(), which takes ha->cs84xx->access_lock and writes op_fw_version on the freed object. Heap spraying that UAF yields arbitrary write and control-flow hijack primitives.
- A:HAvailability impact, high
- Dereferencing the freed cs84xx pointer from sysfs context oopses or panics the kernel even when the UAF is not fully converted into a read/write primitive, so availability impact is complete.