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CVE-2026-72102
dm_early_create: fix freeing used table on dm_resume failure
Published 2026-08-15 (2 months ago) by the Linux kernel CNA. Subsystem drivers/md. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-72102 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
If dm_resume fails, the kernel attempts to free table with dm_table_destroy, but the table was already instantiated with dm_swap_table. This commit skips the call to dm_table_destroy in this case.
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/md/dm-ioctl.c
- What this is
- DEVICE-MAPPER (LVM)MAINTAINERS section matched on drivers/md/dm* · dm-devel@lists.linux.dev · Maintained
- Kernel module
- dm_mod
Check it on the machine
grep -wE 'CONFIG_BLK_DEV_DM|CONFIG_MD' /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 dm_modPrints 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 as a loadable module. Every release below compiles it as a module on every flavour, so whether the code is in the running kernel depends on whether that module is loaded.
- bookworm, trixie, forky, sidm
- m
- a loadable module on every flavour - check lsmod, can be blacklisted
- Build switches
- CONFIG_BLK_DEV_DM, CONFIG_MD
- 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
- 2026-08-15 (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 5.8% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/md
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 5.1 | 5.10.261 | 3ba377a47a09 |
| 5.1 | 5.15.212 | 72c3283a2abd |
| 5.1 | 6.1.178 | d6066145347e |
| 5.1 | 6.6.145 | 259ce9e3fc3a |
| 5.1 | 6.12.97 | 5f6500d44a91 |
| 5.1 | 6.18.40 | 92e3c93d60be |
| 5.1 | 7.1.5 | 7d8ed7cb844d |
| 5.1 | 7.2 | 366665416f20 |
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 bug is only reachable via the dm-mod.create kernel boot parameter processed in late_initcall dm_init_init() calling dm_early_create(); there is no network, adjacent, ioctl, netlink, or post-boot userspace path into this __init-only device-mapper setup code.
- AC:LAttack complexity, low
- Once dm_swap_table() installs the table, an attacker controlling dm-mod.create can deterministically force dm_resume() to fail (e.g., paired snapshot-origin preresume handover rejection or verity/crypt preresume errors) without races or attacker-uncontrolled memory layout.
- PR:LPrivileges required, low
- dm_early_create() performs no capability or credential checks on its error path; unlike runtime DM_DEV_CREATE ioctls that require CAP_SYS_ADMIN, triggering the post-swap dm_resume failure only needs crafting dm-mod.create table parameters at boot, not real-root dm-ioctl privileges unobtainable via user namespaces.
- UI:NUser interaction, none
- The vulnerable teardown runs automatically during late_initcall once dm-mod.create is present and dm_resume fails; no victim must open files, mount filesystems, or take any interactive action beyond rebooting with the crafted boot configuration.
- S:UScope, unchanged
- The use-after-free and double-free corrupt kernel heap memory during device-mapper early boot setup within the kernel trust boundary; it does not cross VM, container, or IOMMU isolation boundaries into another security authority.
- C:HConfidentiality impact, high
- dm_table_destroy() frees a dm_table still referenced through md->map after dm_swap_table(), creating a kernel heap use-after-free that can expose freed object contents and adjacent kernel memory to subsequent allocations and readers.
- I:HIntegrity impact, high
- UAF on the live dm_table enables heap grooming and corrupts destructor paths invoked during erroneous teardown (dm_table_destroy target dtr hooks, then dm_destroy __unbind), providing memory corruption primitives developable into arbitrary kernel writes or control-flow hijack.
- A:HAvailability impact, high
- Freeing the active table then calling dm_destroy()/__unbind() on the same object causes double-free/use-after-free during boot cleanup, readily producing kernel panics, oopses, or unbootable systems on dm-mod.create rootfs platforms (Android/ChromeOS/embedded).