DEBIAN-CVE-2026-53043

In the Linux kernel, the following vulnerability has been resolved:  ocfs2/dlm: validate qrnumregions in dlmmatchregions()  Patch series "ocfs2/dlm: fix two bugs in dlmmatchregions()".  In dlmmatchregions(), the qrnumregions field from a DLMQUERYREGION network message is used to drive loops over the qrregions buffer without sufficient validation.  This series fixes two issues:  - Patch 1 adds a bounds check to reject messages where qrnumregions   exceeds O2NMMAXREGIONS. The o2net layer only validates message   byte length; it does not constrain field values, so a crafted message   can set qrnumregions up to 255 and trigger out-of-bounds reads past   the 1024-byte qrregions buffer.  - Patch 2 fixes an off-by-one in the local-vs-remote comparison loop,   which uses '<=' instead of '<', reading one entry past the valid range   even when qrnumregions is within bounds.   This patch (of 2):  The qrnumregions field from a DLMQUERYREGION network message is used directly as loop bounds in dlmmatchregions() without checking against O2NMMAXREGIONS.  Since qrregions is sized for at most O2NMMAXREGIONS (32) entries, a crafted message with qrnumregions > 32 causes out-of-bounds reads past the qrregions buffer.  Add a bounds check for qrnumregions before entering the loops.