mmc: core: Fix NULL pointer dereference issue with mmc_blk_reset()

If the mmc_hw_reset() fails, then host->card might be NULL in some cases. Hence, check for reset errors and report it to the caller so that the current request can be aborted and also check for host->card before accessing it so as to prevent NULL pointer dereference issue. Signed-off-by: Sahitya Tummala <[email protected]> Signed-off-by: franciscofranco <[email protected]>
franciscofranco · Oct 6, 2016 · 5529007 · 5529007
1 parent b52afab
commit 5529007
Showing 1 changed file with 7 additions and 1 deletion.
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
@@ -1273,8 +1273,14 @@ static int mmc_blk_reset(struct mmc_blk_data *md, struct mmc_host *host,
 
 	md->reset_done |= type;
 	err = mmc_hw_reset(host);
+	if (err && err != -EOPNOTSUPP) {
+		/* We failed to reset so we need to abort the request */
+		pr_err("%s: %s: failed to reset %d\n", mmc_hostname(host),
+				__func__, err);
+		return -ENODEV;
+	}
 	/* Ensure we switch back to the correct partition */
-	if (err != -EOPNOTSUPP) {
+	if (host->card) {
 		struct mmc_blk_data *main_md = mmc_get_drvdata(host->card);
 		int part_err;