[PATCH v2] ubifs: add check for crypto_shash_tfm_digest

[Chen Ni]

Add check for the return value of crypto_shash_tfm_digest() and return
the error if it fails in order to catch the error.

Fixes: 817aa094842d ("ubifs: support offline signed images")
Signed-off-by: Chen Ni <nichen at iscas.ac.cn>
---
Changelog:

v1 -> v2:

1. Update fix tag.
---
 fs/ubifs/master.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/ubifs/master.c b/fs/ubifs/master.c
index 7adc37c10b6a..a148760fa49e 100644
--- a/fs/ubifs/master.c
+++ b/fs/ubifs/master.c
@@ -67,10 +67,13 @@ static int mst_node_check_hash(const struct ubifs_info *c,
 {
 	u8 calc[UBIFS_MAX_HASH_LEN];
 	const void *node = mst;
+	int ret;
 
-	crypto_shash_tfm_digest(c->hash_tfm, node + sizeof(struct ubifs_ch),
+	ret = crypto_shash_tfm_digest(c->hash_tfm, node + sizeof(struct ubifs_ch),
 				UBIFS_MST_NODE_SZ - sizeof(struct ubifs_ch),
 				calc);
+	if (ret)
+		return ret;
 
 	if (ubifs_check_hash(c, expected, calc))
 		return -EPERM;
-- 
2.25.1