mtd: always initialize 'stats' in struct mtd_oob_ops

As the 'stats' field in struct mtd_oob_ops is used in conditional
expressions, ensure it is always zero-initialized in all such structures
to prevent random stack garbage from being interpreted as a pointer.

Strictly speaking, this problem currently only needs to be fixed for
struct mtd_oob_ops structures subsequently passed to mtd_read_oob().
However, this commit goes a step further and makes all instances of
struct mtd_oob_ops in the tree zero-initialized, in hope of preventing
future problems, e.g. if struct mtd_req_stats gets extended with write
statistics at some point.

Signed-off-by: Michał Kępień <[e-mail]>
Signed-off-by: Miquel Raynal <[e-mail]>
Link: https://lore.kernel.org/linux-mtd/[e-mail]

drivers/mtd/inftlcore.c

···
 int inftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len,
 		   size_t *retlen, uint8_t *buf)
 {
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	int res;
 
 	ops.mode = MTD_OPS_PLACE_OOB;
···
 int inftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
 		    size_t *retlen, uint8_t *buf)
 {
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	int res;
 
 	ops.mode = MTD_OPS_PLACE_OOB;
···
 static int inftl_write(struct mtd_info *mtd, loff_t offs, size_t len,
 		       size_t *retlen, uint8_t *buf, uint8_t *oob)
 {
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	int res;
 
 	ops.mode = MTD_OPS_PLACE_OOB;

drivers/mtd/mtdswap.c

···
 	struct mtdswap_oobdata *data, *data2;
 	int ret;
 	loff_t offset;
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 
 	offset = mtdswap_eb_offset(d, eb);
 
···
 	struct mtdswap_oobdata n;
 	int ret;
 	loff_t offset;
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 
 	ops.ooboffs = 0;
 	ops.oobbuf = (uint8_t *)&n;
···
 	loff_t base, pos;
 	unsigned int *p1 = (unsigned int *)d->page_buf;
 	unsigned char *p2 = (unsigned char *)d->oob_buf;
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	int ret;
 
 	ops.mode = MTD_OPS_AUTO_OOB;

drivers/mtd/nand/onenand/onenand_base.c

···
 	struct onenand_chip *this = mtd->priv;
 	unsigned char *pbuf = buf;
 	int ret;
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 
 	/* Force buffer page aligned */
 	if (len < mtd->writesize) {
···
 		size_t *retlen, u_char *buf)
 {
 	struct onenand_chip *this = mtd->priv;
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	int ret;
 
 	if (FLEXONENAND(this)) {

drivers/mtd/nand/onenand/onenand_bbt.c

···
 	int startblock;
 	loff_t from;
 	size_t readlen;
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	int rgn;
 
 	printk(KERN_INFO "Scanning device for bad blocks\n");

drivers/mtd/nand/raw/nand_bbt.c

···
 			 size_t len)
 {
 	struct mtd_info *mtd = nand_to_mtd(this);
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	int res, ret = 0;
 
 	ops.mode = MTD_OPS_PLACE_OOB;
···
 			  uint8_t *buf, uint8_t *oob)
 {
 	struct mtd_info *mtd = nand_to_mtd(this);
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 
 	ops.mode = MTD_OPS_PLACE_OOB;
 	ops.ooboffs = 0;
···
 {
 	struct mtd_info *mtd = nand_to_mtd(this);
 
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	int ret, page_offset;
 
 	ops.ooblen = mtd->oobsize;
···
 	uint8_t rcode = td->reserved_block_code;
 	size_t retlen, len = 0;
 	loff_t to;
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 
 	ops.ooblen = mtd->oobsize;
 	ops.ooboffs = 0;

drivers/mtd/nand/raw/sm_common.c

···
 static int sm_block_markbad(struct nand_chip *chip, loff_t ofs)
 {
 	struct mtd_info *mtd = nand_to_mtd(chip);
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	struct sm_oob oob;
 	int ret;
 

drivers/mtd/nftlcore.c

···
 		  size_t *retlen, uint8_t *buf)
 {
 	loff_t mask = mtd->writesize - 1;
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	int res;
 
 	ops.mode = MTD_OPS_PLACE_OOB;
···
 		   size_t *retlen, uint8_t *buf)
 {
 	loff_t mask = mtd->writesize - 1;
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	int res;
 
 	ops.mode = MTD_OPS_PLACE_OOB;
···
 		      size_t *retlen, uint8_t *buf, uint8_t *oob)
 {
 	loff_t mask = mtd->writesize - 1;
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	int res;
 
 	ops.mode = MTD_OPS_PLACE_OOB;

drivers/mtd/sm_ftl.c

···
 			  uint8_t *buffer, struct sm_oob *oob)
 {
 	struct mtd_info *mtd = ftl->trans->mtd;
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	struct sm_oob tmp_oob;
 	int ret = -EIO;
 	int try = 0;
···
 			   int zone, int block, int boffset,
 			   uint8_t *buffer, struct sm_oob *oob)
 {
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	struct mtd_info *mtd = ftl->trans->mtd;
 	int ret;
 

drivers/mtd/ssfdc.c

···
 /* Read redundancy area (wrapper to MTD_READ_OOB */
 static int read_raw_oob(struct mtd_info *mtd, loff_t offs, uint8_t *buf)
 {
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	int ret;
 
 	ops.mode = MTD_OPS_RAW;

drivers/mtd/tests/nandbiterrs.c

···
 static int rewrite_page(int log)
 {
 	int err = 0;
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 
 	if (log)
 		pr_info("rewrite page\n");

drivers/mtd/tests/oobtest.c

···
 static int write_eraseblock(int ebnum)
 {
 	int i;
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	int err = 0;
 	loff_t addr = (loff_t)ebnum * mtd->erasesize;
 
···
 static int verify_eraseblock(int ebnum)
 {
 	int i;
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	int err = 0;
 	loff_t addr = (loff_t)ebnum * mtd->erasesize;
 	size_t bitflips;
···
 
 static int verify_eraseblock_in_one_go(int ebnum)
 {
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	int err = 0;
 	loff_t addr = (loff_t)ebnum * mtd->erasesize;
 	size_t len = mtd->oobavail * pgcnt;
···
 	int err = 0;
 	unsigned int i;
 	uint64_t tmp;
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	loff_t addr = 0, addr0;
 
 	printk(KERN_INFO "\n");

drivers/mtd/tests/readtest.c

···
 				err = ret;
 		}
 		if (mtd->oobsize) {
-			struct mtd_oob_ops ops;
+			struct mtd_oob_ops ops = { };
 
 			ops.mode      = MTD_OPS_PLACE_OOB;
 			ops.len       = 0;

fs/jffs2/wbuf.c

···
 {
 	int i, ret;
 	int cmlen = min_t(int, c->oobavail, OOB_CM_SIZE);
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 
 	ops.mode = MTD_OPS_AUTO_OOB;
 	ops.ooblen = NR_OOB_SCAN_PAGES * c->oobavail;
···
 int jffs2_check_nand_cleanmarker(struct jffs2_sb_info *c,
 				 struct jffs2_eraseblock *jeb)
 {
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	int ret, cmlen = min_t(int, c->oobavail, OOB_CM_SIZE);
 
 	ops.mode = MTD_OPS_AUTO_OOB;
···
 				 struct jffs2_eraseblock *jeb)
 {
 	int ret;
-	struct mtd_oob_ops ops;
+	struct mtd_oob_ops ops = { };
 	int cmlen = min_t(int, c->oobavail, OOB_CM_SIZE);
 
 	ops.mode = MTD_OPS_AUTO_OOB;