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 94c13f66e1 ("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@syzkaller.appspotmail.com
Fixes: 00d60fd3b9 ("KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Cc: stable@kernel.org # 4.20
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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: 5208cc8342 ("keys, trusted: fix: *do not* allow duplicate key options")
Fixes: 00d60fd3b9 ("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>
Provide five keyctl functions that permit userspace to make use of the new
key type ops for accessing and driving asymmetric keys.
(*) Query an asymmetric key.
long keyctl(KEYCTL_PKEY_QUERY,
key_serial_t key, unsigned long reserved,
struct keyctl_pkey_query *info);
Get information about an asymmetric key. The information is returned
in the keyctl_pkey_query struct:
__u32 supported_ops;
A bit mask of flags indicating which ops are supported. This is
constructed from a bitwise-OR of:
KEYCTL_SUPPORTS_{ENCRYPT,DECRYPT,SIGN,VERIFY}
__u32 key_size;
The size in bits of the key.
__u16 max_data_size;
__u16 max_sig_size;
__u16 max_enc_size;
__u16 max_dec_size;
The maximum sizes in bytes of a blob of data to be signed, a signature
blob, a blob to be encrypted and a blob to be decrypted.
reserved must be set to 0. This is intended for future use to hand
over one or more passphrases needed unlock a key.
If successful, 0 is returned. If the key is not an asymmetric key,
EOPNOTSUPP is returned.
(*) Encrypt, decrypt, sign or verify a blob using an asymmetric key.
long keyctl(KEYCTL_PKEY_ENCRYPT,
const struct keyctl_pkey_params *params,
const char *info,
const void *in,
void *out);
long keyctl(KEYCTL_PKEY_DECRYPT,
const struct keyctl_pkey_params *params,
const char *info,
const void *in,
void *out);
long keyctl(KEYCTL_PKEY_SIGN,
const struct keyctl_pkey_params *params,
const char *info,
const void *in,
void *out);
long keyctl(KEYCTL_PKEY_VERIFY,
const struct keyctl_pkey_params *params,
const char *info,
const void *in,
const void *in2);
Use an asymmetric key to perform a public-key cryptographic operation
a blob of data.
The parameter block pointed to by params contains a number of integer
values:
__s32 key_id;
__u32 in_len;
__u32 out_len;
__u32 in2_len;
For a given operation, the in and out buffers are used as follows:
Operation ID in,in_len out,out_len in2,in2_len
======================= =============== =============== ===========
KEYCTL_PKEY_ENCRYPT Raw data Encrypted data -
KEYCTL_PKEY_DECRYPT Encrypted data Raw data -
KEYCTL_PKEY_SIGN Raw data Signature -
KEYCTL_PKEY_VERIFY Raw data - Signature
info is a string of key=value pairs that supply supplementary
information.
The __spare space in the parameter block must be set to 0. This is
intended, amongst other things, to allow the passing of passphrases
required to unlock a key.
If successful, encrypt, decrypt and sign all return the amount of data
written into the output buffer. Verification returns 0 on success.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Denis Kenzior <denkenz@gmail.com>
Tested-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
Eric Biggers