4.20-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Biggers <ebiggers@xxxxxxxxxx>
commit 57b0e31453209d746c99e513d80b3d0c44a80891 upstream.
We need to check the return value of match_token() for Opt_err before
doing anything with it.
[ Not only did the old "-1" value for Opt_err cause problems for the
__test_and_set_bit(), as fixed in commit 94c13f66e13c ("security:
don't use a negative Opt_err token index"), but accessing
"args[0].from" is invalid for the Opt_err case, as pointed out by Eric
later. - Linus ]
Reported-by: syzbot+a22e0dc07567662c50bc@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 00d60fd3b932 ("KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]")
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Cc: stable@xxxxxxxxxx # 4.20
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
security/keys/keyctl_pkey.c | 2 ++
1 file changed, 2 insertions(+)
--- a/security/keys/keyctl_pkey.c
+++ b/security/keys/keyctl_pkey.c
@@ -50,6 +50,8 @@ static int keyctl_pkey_params_parse(stru
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;
