CVE-2026-90259

In the Linux kernel, the following vulnerability has been resolved: btrfs: qgroup: fix a wrong length calculation in qgroup_free_reserved_data() In that function, we round down the start position and round up the ending position. But during the calculation of @len, we use "round_up(start + len, sectorsize)", which is the rounded up end position, not the rounded up length. Which results a much larger length, and later we are still using "start + len", which is completely incorrect. Fix it by declaring a local @aligned_start and @aligned_len and use them instead.

• https://git.kernel.org/stable/c/9102b179512e11644fb0489ae62010a09afa199c
• https://git.kernel.org/stable/c/c4c136555ff90f1e2921cc42da43daac0ef9985e
• https://git.kernel.org/stable/c/e6edde29990af8064b9d12217ec03db231ccd55d