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Fencer Vulns
no cvss —

CVE-2022-50766 json

btrfs: set generation before calling btrfs_clean_tree_block in btrfs_init_new_buffer

published 2025-12-24 10 mo ago modified 2026-06-17 4 mo ago also EUVD-2022-55795

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 14%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

btrfs: set generation before calling btrfs_clean_tree_block in btrfs_init_new_buffer

syzbot is reporting uninit-value in btrfs_clean_tree_block() [1], for commit bc877d285ca3dba2 ("btrfs: Deduplicate extent_buffer init code") missed that btrfs_set_header_generation() in btrfs_init_new_buffer() must not be moved to after clean_tree_block() because clean_tree_block() is calling btrfs_header_generation() since commit 55c69072d6bd5be1 ("Btrfs: Fix extent_buffer usage when nodesize != leafsize").

Since memzero_extent_buffer() will reset "struct btrfs_header" part, we can't move btrfs_set_header_generation() to before memzero_extent_buffer(). Just re-add btrfs_set_header_generation() before btrfs_clean_tree_block().

Patch / fix

  • Linux Linux 5.15.75, 5.19.17, 6.0.3, 6.1
  • linux Debian 14, Debian 13, Debian 12 6.0.3-1

debian advisories DEBIAN-CVE-2022-50766

  • linux Ubuntu 22.04 LTS 5.15.0-60.66
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1030.34
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1029.36
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1027.32
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1025.28
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1028.33
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1033.40
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1015.19

ubuntu advisories UBUNTU-CVE-2022-50766

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-50766 updated cvss 5.5

kernel: btrfs: set generation before calling btrfs_clean_tree_block in btrfs_init_new_buffer

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 14% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.