kernel: gfs2: Fix NULL pointer dereference in gfs2_log_flush

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...