security: don't use a negative Opt_err token index

The code uses a bitmap to check for duplicate tokens during parsing, and
that doesn't work at all for the negative Opt_err token case.

There is absolutely no reason to make Opt_err be negative, and in fact
it only confuses things, since some of the affected functions actually
return a positive Opt_xyz enum _or_ a regular negative error code (eg
-EINVAL), and using -1 for Opt_err makes no sense.

There are similar problems in ima_policy.c and key encryption, but they
don't have the immediate bug wrt bitmap handing, and ima_policy.c in
particular needs a different patch to make the enum values match the
token array index.  Mimi is sending that separately.

Reported-by: syzbot+a22e0dc07567662c50bc@syzkaller.appspotmail.com
Reported-by: Eric Biggers <ebiggers@kernel.org>
Fixes: 5208cc83423d ("keys, trusted: fix: *do not* allow duplicate key options")
Fixes: 00d60fd3b932 ("KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]")
Cc: James Morris James Morris <jmorris@namei.org>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/security/keys/keyctl_pkey.c b/security/keys/keyctl_pkey.c
index 783978842f13a78805718015f1442bc61ca1b9ca..70e65a2ff2073a5d65cd20fb07b5accce4684955 100644 (file)
--- a/security/keys/keyctl_pkey.c
+++ b/security/keys/keyctl_pkey.c
@@ -25,7 +25,7 @@ static void keyctl_pkey_params_free(struct kernel_pkey_params *params)
 }
 
 enum {
-       Opt_err = -1,
+       Opt_err,
        Opt_enc,                /* "enc=<encoding>" eg. "enc=oaep" */
        Opt_hash,               /* "hash=<digest-name>" eg. "hash=sha1" */
 };

diff --git a/security/keys/trusted.c b/security/keys/trusted.c
index ff6789365a12fb15ed91e160ba2936262ec5c29c..697bfc6c819236c39b828fc786cd6d08ff7bd592 100644 (file)
--- a/security/keys/trusted.c
+++ b/security/keys/trusted.c
@@ -711,7 +711,7 @@ static int key_unseal(struct trusted_key_payload *p,
 }
 
 enum {
-       Opt_err = -1,
+       Opt_err,
        Opt_new, Opt_load, Opt_update,
        Opt_keyhandle, Opt_keyauth, Opt_blobauth,
        Opt_pcrinfo, Opt_pcrlock, Opt_migratable,