net/9p: Fix crash due to bad mount parameters.

It is not safe to use match_int without checking the token type returned
by match_token (especially when the token type returned is Opt_err and
args is empty). Fix it.

Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 6 deletions

diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index a2a1814c7a8d..8c2588e4edc0 100644
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -735,12 +735,14 @@ static int parse_opts(char *params, struct p9_fd_opts *opts)
                 if (!*p)
                         continue;
                 token = match_token(p, tokens, args);
-                r = match_int(&args[0], &option);
-                if (r < 0) {
-                        P9_DPRINTK(P9_DEBUG_ERROR,
-                         "integer field, but no integer?\n");
-                        ret = r;
-                        continue;
+                if (token != Opt_err) {
+                        r = match_int(&args[0], &option);
+                        if (r < 0) {
+                                P9_DPRINTK(P9_DEBUG_ERROR,
+                                "integer field, but no integer?\n");
+                                ret = r;
+                                continue;
+                        }
                 }
                 switch (token) {
                 case Opt_port: