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CVE-2026-53049
gfs2: add some missing log locking
Published 2026-06-24 (4 months ago) by the Linux kernel CNA. Subsystem fs/gfs2. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-53049 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-4665-1 · 2026-07-03 · text | 6.1.176-1 | Update the kernel and reboot. DLA-4665-1 shipped the fix on 2026-07-03, in 6.1.176-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.94-1 | Update the kernel and reboot. Fixed in 6.12.94-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.0.10-1 | Update the kernel and reboot. Fixed in 7.0.10-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.0.10-1 | Update the kernel and reboot. Fixed in 7.0.10-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
Function gfs2_logd() calls the log flushing functions gfs2_ail1_start(), gfs2_ail1_wait(), and gfs2_ail1_empty() without holding sdp->sd_log_flush_lock, but these functions require exclusion against concurrent transactions. To fix that, add a non-locking __gfs2_log_flush() function. Then, in gfs2_logd(), take sdp->sd_log_flush_lock before calling the above mentioned log flushing functions and __gfs2_log_flush().
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.
fs/gfs2/log.c
- What this is
- GFS2 FILE SYSTEMMAINTAINERS section matched on fs/gfs2/ · gfs2@lists.linux.dev · Supported
- Kernel module
- gfs2
Check it on the machine
grep -w CONFIG_GFS2_FS /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 gfs2Prints 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.
- bookworm, trixie, forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64
- M
- a module where it is built at all; some flavours do not build it
- Build switch
- CONFIG_GFS2_FS
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
- 2026-06-24 (4 months ago)source
- CVSS
- 9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- network (AV:N)source
- EPSS
- 0.39%, higher than 31.3% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- fs/gfs2
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 5.7 | 5.15.209 | 3b28eb75afe5 |
| 5.7 | 6.1.175 | ca95342cb1b3 |
| 5.7 | 6.6.141 | bf5fcd9c37c2 |
| 5.7 | 6.12.91 | f2f225cf505a |
| 5.7 | 6.18.33 | 49d9be0722da |
| 5.7 | 7.0.10 | 98e8bf249c79 |
| 5.7 | 7.1 | fe2c8d051150 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4671-1 | 2026-07-05 | bullseye 6.1.176-1~deb11u1 | tracker |
| DLA-4665-1 | 2026-07-03 | bookworm 6.1.176-1 | 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:NAttack vector, network
- GFS2 can back kernel NFS/ksmbd exports, and remote file create/write/unlink requests reach the GFS2 VFS paths that create transactions and wake gfs2_logd. A remote attacker therefore does not need local code execution on a reasonably deployed file server using GFS2 storage.
- AC:LAttack complexity, low
- The race is driven by ordinary concurrent filesystem activity and log pressure, which an attacker can create by issuing repeated parallel writes/metadata operations. No rare hardware state or uncontrollable timing condition is required beyond normal kernel scheduling.
- PR:NPrivileges required, none
- In the highest reasonable deployment, a writable NFS export or guest/share can allow anonymous or unauthenticated remote write activity to reach these paths. No kernel capability or local administrative privilege is required to trigger the vulnerable log/transaction interaction in that scenario.
- UI:NUser interaction, none
- Once the GFS2 filesystem is mounted/exported, exploitation only requires attacker-initiated filesystem operations. No separate victim action is needed during the attack.
- S:UScope, unchanged
- The affected component is the host kernel filesystem implementation, and the impact remains within that kernel/filesystem security authority. This is not a VM escape, IOMMU bypass, or cross-authority boundary violation.
- C:HConfidentiality impact, high
- The missing exclusion can corrupt GFS2 log/revoke and AIL state, making stale or incorrect filesystem contents plausibly reachable after replay or recovery. Under the required uncertainty rule, filesystem journal corruption that can expose arbitrary stored data is scored as high confidentiality impact.
- I:HIntegrity impact, high
- The bug affects journal/log bookkeeping that protects filesystem metadata and replay ordering, so a triggered race can corrupt or roll back arbitrary filesystem state. This is high integrity impact for a shared GFS2 volume.
- A:HAvailability impact, high
- The race can lead to GFS2 withdraws, hangs, assertion failures, or filesystem unavailability under log flushing pressure. That is a high availability impact for the affected kernel/filesystem instance.