[PATCH] KEYS: fix parsing invalid pkey info string

[Eric Biggers]

From: Eric Biggers <ebiggers at google.com>

We need to check the return value of match_token() for Opt_err (-1)
before doing anything with it.

Reported-by: syzbot+a22e0dc07567662c50bc at syzkaller.appspotmail.com
Fixes: 00d60fd3b932 ("KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]")
Signed-off-by: Eric Biggers <ebiggers at google.com>
---
 security/keys/keyctl_pkey.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/security/keys/keyctl_pkey.c b/security/keys/keyctl_pkey.c
index 783978842f13a..987fac8051d70 100644
--- a/security/keys/keyctl_pkey.c
+++ b/security/keys/keyctl_pkey.c
@@ -50,6 +50,8 @@ static int keyctl_pkey_params_parse(struct kernel_pkey_params *params)
 		if (*p == '\0' || *p == ' ' || *p == '\t')
 			continue;
 		token = match_token(p, param_keys, args);
+		if (token == Opt_err)
+			return -EINVAL;
 		if (__test_and_set_bit(token, &token_mask))
 			return -EINVAL;
 		q = args[0].from;
-- 
2.19.1