KEYS: DH: don't feed uninitialized "otherinfo" into KDF
authorEric Biggers <ebiggers@google.com>
Thu, 8 Jun 2017 13:49:42 +0000 (14:49 +0100)
committerJames Morris <james.l.morris@oracle.com>
Fri, 9 Jun 2017 03:29:49 +0000 (13:29 +1000)
commit281590b4221779dbc4a5e2c33c0c5b0239cfe794
tree3abf0a758a569c41c972f5c79f31337ad7a04fae
parentbbe240454d86be95151e0ecfd6ac55fe5ef5a6f5
KEYS: DH: don't feed uninitialized "otherinfo" into KDF

If userspace called KEYCTL_DH_COMPUTE with kdf_params containing NULL
otherinfo but nonzero otherinfolen, the kernel would allocate a buffer
for the otherinfo, then feed it into the KDF without initializing it.
Fix this by always doing the copy from userspace (which will fail with
EFAULT in this scenario).

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: James Morris <james.l.morris@oracle.com>
security/keys/dh.c