CVE-2026-90260

CVE CVE-2026-90260EUVD EUVD-2026-81853Published 2026-09-17T16:07:58.000ZLast changed 2026-09-18T17:54:13.000ZCVSS 7.1

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: btrfs: zoned: don't clobber the extent buffer when zeroing it out On a zoned filesystem a freed-but-still-dirty tree block is written out as zeros (EXTENT_BUFFER_ZONED_ZEROOUT) only to keep the zone write pointer advancing. btree_csum_one_bio() implemented this by memzeroing the extent buffer's own folios before submission. That destroys the in-memory buffer while it may still be referenced. In particular btrfs_free_tree_block() can run on it afterwards and reads the header to add a delayed reference; once the header has been zeroed it frees bytenr 0 and corrupts the extent tree (the btrfs_header_bytenr(buf) != 0 ASSERT in btrfs_free_tree_block(), or an "unable to find ref" abort). It is flaky and reproduces under fsstress, e.g. generic/461 and generic/013. Write the zeros to disk from the shared zero page instead and leave the extent buffer content untouched, so any later reference - including the delayed reference from btrfs_free_tree_block() - still sees a valid header. end_bbio_meta_write() now clears writeback on the buffer's own folios, as the bio no longer carries them.

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 aa6313e6ff2bfbf736a2739047bba355d8241584 <92484ad014f2e2b0e0e7bbc1610951e978cf557c; 6.8; patch: 0; patch: 7.2.6; patch: 6.18.52; aa6313e6ff2bfbf736a2739047bba355d8241584 <db4b9eefc8ee0bcaeee4d5e6a7313905f6a2fe7c; aa6313e6ff2bfbf736a2739047bba355d8241584 <98e3747587f9f87f010d8d7e55786216249a94af; patch: 7.3-rc1

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

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Linux — Linux

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