[PATCH] ubifs: Do not skip hash checking in data nodes

Sascha Hauer s.hauer at pengutronix.de
Mon Apr 1 06:00:44 PDT 2019


UBIFS bails out early from try_read_node() when it doesn't have to check
the CRC. Still the node hash has to be checked, otherwise wrong data
could be sneaked into the FS. Fix this by not bailing out early and
always checking the node hash.

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 fs/ubifs/tnc.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c
index 25572ffea163..ebf8c26f5b22 100644
--- a/fs/ubifs/tnc.c
+++ b/fs/ubifs/tnc.c
@@ -479,14 +479,13 @@ static int try_read_node(const struct ubifs_info *c, void *buf, int type,
 	if (node_len != len)
 		return 0;
 
-	if (type == UBIFS_DATA_NODE && c->no_chk_data_crc && !c->mounting &&
-	    !c->remounting_rw)
-		return 1;
-
-	crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8);
-	node_crc = le32_to_cpu(ch->crc);
-	if (crc != node_crc)
-		return 0;
+	if (type != UBIFS_DATA_NODE || !c->no_chk_data_crc || c->mounting ||
+	    c->remounting_rw) {
+		crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8);
+		node_crc = le32_to_cpu(ch->crc);
+		if (crc != node_crc)
+			return 0;
+	}
 
 	err = ubifs_node_check_hash(c, buf, zbr->hash);
 	if (err) {
-- 
2.20.1




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