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author | Eric Biggers <ebiggers@google.com> | 2019-01-06 18:47:43 -0800 |
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committer | Herbert Xu <herbert@gondor.apana.org.au> | 2019-01-18 18:40:24 +0800 |
commit | e1fe27571442ae7e9114429d38d6b561941f2776 (patch) | |
tree | b267527a613e6d6ace9733119f24a61e88e4e263 /crypto/shash.c | |
parent | 876a053bb3938fd7b35beec1081d1db2f62a4113 (diff) | |
download | linux-crypto-e1fe27571442ae7e9114429d38d6b561941f2776.tar.gz linux-crypto-e1fe27571442ae7e9114429d38d6b561941f2776.zip |
crypto: skcipher - set CRYPTO_TFM_NEED_KEY if ->setkey() fails
Some algorithms have a ->setkey() method that is not atomic, in the
sense that setting a key can fail after changes were already made to the
tfm context. In this case, if a key was already set the tfm can end up
in a state that corresponds to neither the old key nor the new key.
For example, in lrw.c, if gf128mul_init_64k_bbe() fails due to lack of
memory, then priv::table will be left NULL. After that, encryption with
that tfm will cause a NULL pointer dereference.
It's not feasible to make all ->setkey() methods atomic, especially ones
that have to key multiple sub-tfms. Therefore, make the crypto API set
CRYPTO_TFM_NEED_KEY if ->setkey() fails and the algorithm requires a
key, to prevent the tfm from being used until a new key is set.
[Cc stable mainly because when introducing the NEED_KEY flag I changed
AF_ALG to rely on it; and unlike in-kernel crypto API users, AF_ALG
previously didn't have this problem. So these "incompletely keyed"
states became theoretically accessible via AF_ALG -- though, the
opportunities for causing real mischief seem pretty limited.]
Fixes: afef2cfab1cc ("crypto: skcipher - prevent using skciphers without setting key")
Cc: <stable@vger.kernel.org> # v4.16+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to '')
0 files changed, 0 insertions, 0 deletions