CVE-2026-68442

CVE CVE-2026-68442EUVD EUVD-2026-57050Published 2026-08-12T00:07:31.000ZLast changed 2026-08-17T05:05:39.000ZCVSS 7.8

What the advisory describes

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.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

Linux — Linux patch: 6.12.101; f86f7a75e2fb5fd7d31d00eab8a392f97ba42ce9 <2a9246a424f45f33a1b8367052611ebe874868ad; f86f7a75e2fb5fd7d31d00eab8a392f97ba42ce9 <5eff4d5b17fa1950e80bfd1ba43dc0699e61a644; patch: 6.18.42; 6.8; patch: 7.2; patch: 7.1.6; f86f7a75e2fb5fd7d31d00eab8a392f97ba42ce9 <9304713b70e7e1450e3a76e758836fe5391bfa95; patch: 0; f86f7a75e2fb5fd7d31d00eab8a392f97ba42ce9 <0e465c63f103a5ce6849614d6bda048d70eebec8

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

Linux — Linux

Does this concern one of your customers?

This page cannot answer that — it does not know your estate. Whoever has recorded their environments gets the answer the morning after publication, together with a paragraph they can forward to the customer unedited.

Try it for 28 days

Patchlage reports hits and suspected hits. About everything else this system says nothing — neither this page nor the situation report ever claims that an estate is safe.