In the Linux kernel, the following vulnerability has been resolved:
btrfs: don't propagate EXTENT_FLAG_LOGGING to split extent maps
When btrfs_drop_extent_map_range() splits an extent map, the new split maps inherit the original map's flags through a local 'flags' variable. Commit f86f7a75e2fb ("btrfs: use the flags of an extent map to identify the compression type") changed the EXTENT_FLAG_LOGGING clearing to operate on em->flags instead of that local 'flags' copy, so a split of an extent map that is currently being logged wrongly inherits EXTENT_FLAG_LOGGING.
The flag is then never cleared on the split, and when it is freed while still on the inode's modified_extents list (for example by the extent map shrinker) it trips the WARN_ON(!list_empty(&em->list)) in btrfs_free_extent_map() and leads to a use-after-free.
Clear EXTENT_FLAG_LOGGING from the local 'flags' copy used for the splits and only clear EXTENT_FLAG_PINNED from em->flags, restoring the behaviour prior to f86f7a75e2fb.
CVSS Details
- CVSS 3.1 Base Score: 7.8
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon_linux_2023 | — | Upgrade kernel6.12-headersUpgrade perf6.12Upgrade kernel6.12-modules-extra-commonUpgrade kernel-livepatch-6.12.103-127.188Upgrade kernel6.12-debuginfoUpgrade kernel6.12-toolsUpgrade bpftool6.12-debuginfoUpgrade perf6.12-debuginfoUpgrade kernel6.12-tools-develUpgrade kernel6.12-modules-extraUpgrade kernel6.12-debuginfo-common-aarch64Upgrade kernel6.12-debuginfo-common-x86_64Upgrade bpftool6.12Upgrade python3-perf6.12-debuginfoUpgrade python3-perf6.12Upgrade kernel6.12Upgrade kernel6.12-develUpgrade kernel6.12-tools-debuginfo | Sep 1, 2026 | Aug 12, 2026 |
| Debian | — | Upgrade linuxUpgrade linux-6.12 | Aug 13, 2026 | Aug 13, 2026 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Aug 17, 2026 | Aug 12, 2026 |
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