DEBIAN-CVE-2025-39738

In the Linux kernel, the following vulnerability has been resolved: btrfs: do not allow relocation of partially dropped subvolumes [BUG] There is an internal report that balance triggered transaction abort, with the following call trace: item 85 key (594509824 169 0) itemoff 12599 itemsize 33 extent refs 1 gen 197740 flags 2 ref#0: tree block backref root 7 item 86 key (594558976 169 0) itemoff 12566 itemsize 33 extent refs 1 gen 197522 flags 2 ref#0: tree block backref root 7 ... BTRFS error (device loop0): extent item not found for insert, bytenr 594526208 numbytes 16384 parent 449921024 rootobjectid 934 owner 1 offset 0 BTRFS error (device loop0): failed to run delayed ref for logical 594526208 numbytes 16384 type 182 action 1 refmod 1: -117 ------------[ cut here ]------------ BTRFS: Transaction aborted (error -117) WARNING: CPU: 1 PID: 6963 at ../fs/btrfs/extent-tree.c:2168 btrfsrundelayedrefs+0xfa/0x110 [btrfs] And btrfs check doesn't report anything wrong related to the extent tree. [CAUSE] The cause is a little complex, firstly the extent tree indeed doesn't have the backref for 594526208. The extent tree only have the following two backrefs around that bytenr on-disk: item 65 key (594509824 METADATAITEM 0) itemoff 13880 itemsize 33 refs 1 gen 197740 flags TREEBLOCK tree block skinny level 0 (176 0x7) tree block backref root CSUMTREE item 66 key (594558976 METADATAITEM 0) itemoff 13847 itemsize 33 refs 1 gen 197522 flags TREEBLOCK tree block skinny level 0 (176 0x7) tree block backref root CSUMTREE But the such missing backref item is not an corruption on disk, as the offending delayed ref belongs to subvolume 934, and that subvolume is being dropped: item 0 key (934 ROOTITEM 198229) itemoff 15844 itemsize 439 generation 198229 rootdirid 256 bytenr 10741039104 bytelimit 0 bytesused 345571328 lastsnapshot 198229 flags 0x1000000000001(RDONLY) refs 0 dropprogress key (206324 EXTENTDATA 2711650304) droplevel 2 level 2 generationv2 198229 And that offending tree block 594526208 is inside the dropped range of that subvolume. That explains why there is no backref item for that bytenr and why btrfs check is not reporting anything wrong. But this also shows another problem, as btrfs will do all the orphan subvolume cleanup at a read-write mount. So half-dropped subvolume should not exist after an RW mount, and balance itself is also exclusive to subvolume cleanup, meaning we shouldn't hit a subvolume half-dropped during relocation. The root cause is, there is no orphan item for this subvolume. In fact there are 5 subvolumes from around 2021 that have the same problem. It looks like the original report has some older kernels running, and caused those zombie subvolumes. Thankfully upstream commit 8d488a8c7ba2 ("btrfs: fix subvolume/snapshot deletion not triggered on mount") has long fixed the bug. [ENHANCEMENT] For repairing such old fs, btrfs-progs will be enhanced. Considering how delayed the problem will show up (at run delayed ref time) and at that time we have to abort transaction already, it is too late. Instead here we reject any half-dropped subvolume for reloc tree at the earliest time, preventing confusion and extra time wasted on debugging similar bugs.

References

https://security-tracker.debian.org/tracker/CVE-2025-39738

Affected packages

Debian:11 / linux

Package

Name: linux
Purl: pkg:deb/debian/linux?arch=source

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

5.*

5.10.46-4

5.10.46-5

5.10.70-1~bpo10+1

5.10.70-1

5.10.84-1

5.10.92-1~bpo10+1

5.10.92-1

5.10.92-2

5.10.103-1~bpo10+1

5.10.103-1

5.10.106-1

5.10.113-1

5.10.120-1~bpo10+1

5.10.120-1

5.10.127-1

5.10.127-2~bpo10+1

5.10.127-2

5.10.136-1

5.10.140-1

5.10.148-1

5.10.149-1

5.10.149-2

5.10.158-1

5.10.158-2

5.10.162-1

5.10.178-1

5.10.178-2

5.10.178-3

5.10.179-1

5.10.179-2

5.10.179-3

5.10.179-4

5.10.179-5

5.10.191-1

5.10.197-1

5.10.205-1

5.10.205-2

5.10.209-1

5.10.209-2

5.10.216-1

5.10.218-1

5.10.221-1

5.10.223-1

5.10.226-1

5.10.234-1

5.10.237-1

5.10.244-1

5.13.9-1~exp1

5.13.9-1~exp2

5.13.12-1~exp1

5.14-1~exp1

5.14-1~exp2

5.14.1-1~exp1

5.14.2-1~exp1

5.14.3-1~exp1

5.14.6-1

5.14.6-2

5.14.6-3

5.14.9-1

5.14.9-2~bpo11+1

5.14.9-2

5.14.12-1

5.14.16-1

5.15-1~exp1

5.15.1-1~exp1

5.15.2-1~exp1

5.15.3-1

5.15.5-1

5.15.5-2~bpo11+1

5.15.5-2

5.15.15-1

5.15.15-2~bpo11+1

5.15.15-2

5.16~rc1-1~exp1

5.16~rc3-1~exp1

5.16~rc4-1~exp1

5.16~rc5-1~exp1

5.16~rc6-1~exp1

5.16~rc7-1~exp1

5.16~rc8-1~exp1

5.16.3-1~exp1

5.16.4-1~exp1

5.16.7-1

5.16.7-2

5.16.10-1

5.16.11-1~bpo11+1

5.16.11-1

5.16.12-1~bpo11+1

5.16.12-1

5.16.14-1

5.16.18-1

5.17~rc3-1~exp1

5.17~rc4-1~exp1

5.17~rc5-1~exp1

5.17~rc6-1~exp1

5.17~rc7-1~exp1

5.17~rc8-1~exp1

5.17.1-1~exp1

5.17.3-1

5.17.6-1

5.17.11-1

5.18-1~exp1

5.18.2-1~bpo11+1

5.18.2-1

5.18.5-1

5.18.14-1~bpo11+1

5.18.14-1

5.18.16-1~bpo11+1

5.18.16-1

5.19~rc4-1~exp1

5.19~rc6-1~exp1

5.19-1~exp1

5.19.6-1

5.19.11-1~bpo11+1

5.19.11-1

6.*

6.0~rc7-1~exp1

6.0-1~exp1

6.0.2-1

6.0.3-1~bpo11+1

6.0.3-1

6.0.5-1

6.0.6-1

6.0.6-2

6.0.7-1

6.0.8-1

6.0.10-1

6.0.10-2

6.0.12-1~bpo11+1

6.0.12-1

6.0.12-1+alpha

6.1~rc3-1~exp1

6.1~rc5-1~exp1

6.1~rc6-1~exp1

6.1~rc7-1~exp1

6.1~rc8-1~exp1

6.1.1-1~exp1

6.1.1-1~exp2

6.1.2-1~exp1

6.1.4-1

6.1.7-1

6.1.8-1

6.1.8-1+sh4

6.1.11-1

6.1.12-1~bpo11+1

6.1.12-1

6.1.15-1~bpo11+1

6.1.15-1

6.1.20-1~bpo11+1

6.1.20-1

6.1.20-2~bpo11+1

6.1.20-2

6.1.25-1

6.1.27-1~bpo11+1

6.1.27-1

6.1.37-1

6.1.38-1

6.1.38-2~bpo11+1

6.1.38-2

6.1.38-3

6.1.38-4~bpo11+1

6.1.38-4

6.1.52-1

6.1.55-1~bpo11+1

6.1.55-1

6.1.64-1

6.1.66-1

6.1.67-1

6.1.69-1~bpo11+1

6.1.69-1

6.1.76-1~bpo11+1

6.1.76-1

6.1.82-1

6.1.85-1

6.1.90-1~bpo11+1

6.1.90-1

6.1.94-1~bpo11+1

6.1.94-1

6.1.98-1

6.1.99-1

6.1.106-1

6.1.106-2

6.1.106-3

6.1.112-1

6.1.115-1

6.1.119-1

6.1.123-1

6.1.124-1

6.1.128-1

6.1.129-1

6.1.133-1

6.1.135-1

6.1.137-1

6.1.139-1

6.1.140-1

6.1.147-1

6.1.148-1

6.1.153-1

6.3.1-1~exp1

6.3.2-1~exp1

6.3.4-1~exp1

6.3.5-1~exp1

6.3.7-1~bpo12+1

6.3.7-1

6.3.11-1

6.4~rc6-1~exp1

6.4~rc7-1~exp1

6.4.1-1~exp1

6.4.4-1~bpo12+1

6.4.4-1

6.4.4-2

6.4.4-3~bpo12+1

6.4.4-3

6.4.11-1

6.4.13-1

6.5~rc4-1~exp1

6.5~rc6-1~exp1

6.5~rc7-1~exp1

6.5.1-1~exp1

6.5.3-1~bpo12+1

6.5.3-1

6.5.6-1

6.5.8-1

6.5.10-1~bpo12+1

6.5.10-1

6.5.13-1

6.6.3-1~exp1

6.6.4-1~exp1

6.6.7-1~exp1

6.6.8-1

6.6.9-1

6.6.11-1

6.6.13-1~bpo12+1

6.6.13-1

6.6.15-1

6.6.15-2

6.7-1~exp1

6.7.1-1~exp1

6.7.4-1~exp1

6.7.7-1

6.7.9-1

6.7.9-2

6.7.12-1~bpo12+1

6.7.12-1

6.8.9-1

6.8.11-1

6.8.12-1~bpo12+1

6.8.12-1

6.9.2-1~exp1

6.9.7-1~bpo12+1

6.9.7-1

6.9.8-1

6.9.9-1

6.9.10-1~bpo12+1

6.9.10-1

6.9.11-1

6.9.12-1

6.10-1~exp1

6.10.1-1~exp1

6.10.3-1

6.10.4-1

6.10.6-1~bpo12+1

6.10.6-1

6.10.7-1

6.10.9-1

6.10.11-1~bpo12+1

6.10.11-1

6.10.12-1

6.11~rc4-1~exp1

6.11~rc5-1~exp1

6.11-1~exp1

6.11.2-1

6.11.4-1

6.11.5-1~bpo12+1

6.11.5-1

6.11.6-1

6.11.7-1

6.11.9-1

6.11.10-1~bpo12+1

6.11.10-1

6.12~rc6-1~exp1

6.12.3-1

6.12.5-1

6.12.6-1

6.12.8-1

6.12.9-1~bpo12+1

6.12.9-1

6.12.9-1+alpha

6.12.10-1

6.12.11-1

6.12.11-1+alpha

6.12.11-1+alpha.1

6.12.12-1~bpo12+1

6.12.12-1

6.12.13-1

6.12.15-1

6.12.16-1

6.12.17-1

6.12.19-1

6.12.20-1

6.12.21-1

6.12.22-1~bpo12+1

6.12.22-1

6.12.25-1

6.12.27-1~bpo12+1

6.12.27-1

6.12.29-1

6.12.30-1~bpo12+1

6.12.30-1

6.12.31-1

6.12.32-1~bpo12+1

6.12.32-1

6.12.33-1~bpo12+1

6.12.33-1

6.12.35-1~bpo12+1

6.12.35-1

6.12.37-1

6.12.38-1~bpo12+1

6.12.38-1

6.12.41-1

6.12.43-1~bpo12+1

6.12.43-1

6.12.48-1

6.13~rc6-1~exp1

6.13~rc7-1~exp1

6.13.2-1~exp1

6.13.3-1~exp1

6.13.4-1~exp1

6.13.5-1~exp1

6.13.6-1~exp1

6.13.7-1~exp1

6.13.8-1~exp1

6.13.9-1~exp1

6.13.10-1~exp1

6.13.11-1~exp1

6.14.3-1~exp1

6.14.5-1~exp1

6.14.6-1~exp1

6.15~rc7-1~exp1

6.15-1~exp1

6.15.1-1~exp1

6.15.2-1~exp1

6.15.3-1~exp1

6.15.4-1~exp1

6.15.5-1~exp1

6.15.6-1~exp1

6.16~rc7-1~exp1

6.16-1~exp1

6.16.1-1~exp1

6.16.3-1~bpo13+1

6.16.3-1

6.16.5-1

6.16.6-1

6.16.7-1

6.16.8-1

6.16.9-1

6.16.10-1

6.16.11-1

6.16.12-1

6.17.2-1~exp1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Debian:12 / linux

Package

Name: linux
Purl: pkg:deb/debian/linux?arch=source

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

6.1.153-1

Affected versions

6.*

6.1.27-1

6.1.37-1

6.1.38-1

6.1.38-2~bpo11+1

6.1.38-2

6.1.38-3

6.1.38-4~bpo11+1

6.1.38-4

6.1.52-1

6.1.55-1~bpo11+1

6.1.55-1

6.1.64-1

6.1.66-1

6.1.67-1

6.1.69-1~bpo11+1

6.1.69-1

6.1.76-1~bpo11+1

6.1.76-1

6.1.82-1

6.1.85-1

6.1.90-1~bpo11+1

6.1.90-1

6.1.94-1~bpo11+1

6.1.94-1

6.1.98-1

6.1.99-1

6.1.106-1

6.1.106-2

6.1.106-3

6.1.112-1

6.1.115-1

6.1.119-1

6.1.123-1

6.1.124-1

6.1.128-1

6.1.129-1

6.1.133-1

6.1.135-1

6.1.137-1

6.1.139-1

6.1.140-1

6.1.147-1

6.1.148-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Debian:13 / linux

Package

Name: linux
Purl: pkg:deb/debian/linux?arch=source

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

6.12.43-1

Affected versions

6.*

6.12.38-1

6.12.41-1

6.12.43-1~bpo12+1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Debian:14 / linux

Package

Name: linux
Purl: pkg:deb/debian/linux?arch=source

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

6.16.3-1

Affected versions

6.*

6.12.38-1

6.12.41-1

6.12.43-1~bpo12+1

6.12.43-1

6.12.48-1

6.13~rc6-1~exp1

6.13~rc7-1~exp1

6.13.2-1~exp1

6.13.3-1~exp1

6.13.4-1~exp1

6.13.5-1~exp1

6.13.6-1~exp1

6.13.7-1~exp1

6.13.8-1~exp1

6.13.9-1~exp1

6.13.10-1~exp1

6.13.11-1~exp1

6.14.3-1~exp1

6.14.5-1~exp1

6.14.6-1~exp1

6.15~rc7-1~exp1

6.15-1~exp1

6.15.1-1~exp1

6.15.2-1~exp1

6.15.3-1~exp1

6.15.4-1~exp1

6.15.5-1~exp1

6.15.6-1~exp1

6.16~rc7-1~exp1

6.16-1~exp1

6.16.1-1~exp1

6.16.3-1~bpo13+1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Debian:11 / linux-6.1

Package

Name: linux-6.1
Purl: pkg:deb/debian/linux-6.1?arch=source

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

6.1.153-1~deb11u1

Affected versions

6.*

6.1.106-3~deb11u1

6.1.106-3~deb11u2

6.1.106-3~deb11u3

6.1.112-1~deb11u1

6.1.119-1~deb11u1

6.1.128-1~deb11u1

6.1.129-1~deb11u1

6.1.137-1~deb11u1

6.1.140-1~deb11u1

6.1.147-1~deb11u1

6.1.148-1~deb11u1

Ecosystem specific

{
    "urgency": "not yet assigned"
}