LU-13466 mgc: protect from NULL exp in mgc_enqueue()

Return an error in mgc_enqueue() is exp parameter is NULL.
Otherwise, it might crash in class_exp2cliimp().

Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: I9be0bf57c6a21c83abb08b261f548128114c33f2
Reviewed-on: https://review.whamcloud.com/38280
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>

diff --git a/lustre/mgc/mgc_request.c b/lustre/mgc/mgc_request.c
index c0fed41..86eeb93 100644 (file)
--- a/lustre/mgc/mgc_request.c
+++ b/lustre/mgc/mgc_request.c
@@ -1100,6 +1100,9 @@ static int mgc_enqueue(struct obd_export *exp, enum ldlm_type type,
        int rc;
        ENTRY;
 
+       if (!exp)
+               RETURN(-EBADR);
+
        CDEBUG(D_MGC, "Enqueue for %s (res %#llx)\n", cld->cld_logname,
                cld->cld_resid.name[0]);