diff mbox series

[3/4] 9p: p9dirent_read: check network-provided name length

Message ID 1536339057-21974-4-git-send-email-asmadeus@codewreck.org (mailing list archive)
State New, archived
Headers show
Series 9p coverity fixes | expand

Commit Message

Dominique Martinet Sept. 7, 2018, 4:50 p.m. UTC 
From: Dominique Martinet <dominique.martinet@cea.fr>

strcpy to dirent->d_name could overflow the buffer, use strscpy to check
the provided string length and error out if the size was too big.

While we are here, make the function return an error when the pdu
parsing failed, instead of returning the pdu offset as if it had been a
success...

Addresses-Coverity-ID: 139133 ("Copy into fixed size buffer")
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
---
 net/9p/protocol.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/net/9p/protocol.c b/net/9p/protocol.c
index b4d80c533f89..462ba144cb39 100644
--- a/net/9p/protocol.c
+++ b/net/9p/protocol.c
@@ -623,13 +623,19 @@  int p9dirent_read(struct p9_client *clnt, char *buf, int len,
 	if (ret) {
 		p9_debug(P9_DEBUG_9P, "<<< p9dirent_read failed: %d\n", ret);
 		trace_9p_protocol_dump(clnt, &fake_pdu);
-		goto out;
+		return ret;
 	}
 
-	strcpy(dirent->d_name, nameptr);
+	ret = strscpy(dirent->d_name, nameptr, sizeof(dirent->d_name));
+	if (ret < 0) {
+		p9_debug(P9_DEBUG_ERROR,
+			 "On the wire dirent name too long: %s\n",
+			 nameptr);
+		kfree(nameptr);
+		return ret;
+	}
 	kfree(nameptr);
 
-out:
 	return fake_pdu.offset;
 }
 EXPORT_SYMBOL(p9dirent_read);