CVE-2026-90118ntfs: fix off-by-one page overflow in ntfs_decompress()

Official description

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 if (cb >= cb_sb_end || dp_addr > dp_sb_end) break; 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.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/b42644e425fed4a5cd6c88372655da5c1b52c666
• https://git.kernel.org/stable/c/98716c9fce21f6c8a9d71e08cf53e7504fa562f4