mtd: mtdswap: fix possible null dereference

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=8d8f26e19cae48541b824f164021e1ff05067f8c
Commit:     8d8f26e19cae48541b824f164021e1ff05067f8c
Parent:     5c8d2607756a63ddf5b2f2dd368851b8febe4e72
Author:     Maxin B. John <john.maxin at nokia.com>
AuthorDate: Fri May 20 15:44:10 2011 +0100
Committer:  David Woodhouse <David.Woodhouse at intel.com>
CommitDate: Wed May 25 02:11:44 2011 +0100

    mtd: mtdswap: fix possible null dereference
    
    This patch fixes the possible null dereference of the variable "oinfo"
    Thanks to Coverity for spotting this.
    
    Signed-off-by: Maxin B. John <john.maxin at nokia.com>
    Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy at nokia.com>
    Signed-off-by: David Woodhouse <David.Woodhouse at intel.com>
---
 drivers/mtd/mtdswap.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/drivers/mtd/mtdswap.c b/drivers/mtd/mtdswap.c
index fed215c..fd78853 100644
--- a/drivers/mtd/mtdswap.c
+++ b/drivers/mtd/mtdswap.c
@@ -1450,7 +1450,13 @@ static void mtdswap_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
 	}
 
 	oinfo = mtd->ecclayout;
-	if (!mtd->oobsize || !oinfo || oinfo->oobavail < MTDSWAP_OOBSIZE) {
+	if (!oinfo) {
+		printk(KERN_ERR "%s: mtd%d does not have OOB\n",
+			MTDSWAP_PREFIX, mtd->index);
+		return;
+	}
+
+	if (!mtd->oobsize || oinfo->oobavail < MTDSWAP_OOBSIZE) {
 		printk(KERN_ERR "%s: Not enough free bytes in OOB, "
 			"%d available, %zu needed.\n",
 			MTDSWAP_PREFIX, oinfo->oobavail, MTDSWAP_OOBSIZE);