CVE-2026-90118 PUBLISHED

ntfs: fix off-by-one page overflow in ntfs_decompress()

Assigner: Linux
Reserved: 11.09.2026 Published: 17.09.2026 Updated: 17.09.2026

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

ntfs: fix off-by-one page overflow in ntfs_decompress()

The per-token range check in ntfs_decompress() uses

<pre>if (cb >= cb_sb_end || dp_addr > dp_sb_end) break; </pre>

so dp_addr == dp_sb_end falls through to the symbol copy *dp_addr++ = *cb++, writing one byte past the destination page. Since NTFS_SB_SIZE == PAGE_SIZE the destination is a single page, so the byte lands in the adjacent page, and *dest_ofs is left one past the sub-block end (the later *dest_ofs &= ~PAGE_MASK then yields 1, not 0, so the page is never finalized and later sub-blocks keep writing further past it). A corrupted compressed $DATA attribute thus produces a bounded run of out-of-bounds writes when the file is read.

Break as soon as dp_addr reaches dp_sb_end; a full sub-block still completes, as its final copy advances dp_addr to exactly dp_sb_end.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 1e9ea7e04472d4e5e12e58c881eaacfb3e49b669 to b42644e425fed4a5cd6c88372655da5c1b52c666 (excl.)
  • affected from 1e9ea7e04472d4e5e12e58c881eaacfb3e49b669 to 98716c9fce21f6c8a9d71e08cf53e7504fa562f4 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 7.1 is affected
  • unaffected from 0 to 7.1 (excl.)
  • unaffected from 7.2.6 to 7.2.* (incl.)
  • unaffected from 7.3-rc1 to * (incl.)

References