In the Linux kernel, the following vulnerability has been resolved: gfs2: Fix NULL pointer dereference in gfs2logflush In gfs2jindexfree(), set sdp->sdjdesc to NULL under the log flush lock to provide exclusion against gfs2logflush(). In gfs2logflush(), check if sdp->sdjdesc is non-NULL before dereferencing it. Otherwise, we could run into a NULL pointer dereference when outstanding glock work races with an unmount (glockworkfunc -> runqueue -> doxmote -> inodegosync -> gfs2logflush).