diff options
| author | Stephan Mueller <smueller@chronox.de> | 2018-01-02 08:55:25 +0100 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2018-01-12 23:03:05 +1100 |
| commit | bb30b8848c85e18ca7e371d0a869e94b3e383bdf (patch) | |
| tree | e6acf772ef0252bf11c2b5035c02110f30b42ceb /crypto/af_alg.c | |
| parent | da1729ce4866be266575a114208c7d5350bf310d (diff) | |
| download | lwn-bb30b8848c85e18ca7e371d0a869e94b3e383bdf.tar.gz lwn-bb30b8848c85e18ca7e371d0a869e94b3e383bdf.zip | |
crypto: af_alg - whitelist mask and type
The user space interface allows specifying the type and mask field used
to allocate the cipher. Only a subset of the possible flags are intended
for user space. Therefore, white-list the allowed flags.
In case the user space caller uses at least one non-allowed flag, EINVAL
is returned.
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/af_alg.c')
| -rw-r--r-- | crypto/af_alg.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/crypto/af_alg.c b/crypto/af_alg.c index 35d4dcea381f..5231f421ad00 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -150,7 +150,7 @@ EXPORT_SYMBOL_GPL(af_alg_release_parent); static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) { - const u32 forbidden = CRYPTO_ALG_INTERNAL; + const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY; struct sock *sk = sock->sk; struct alg_sock *ask = alg_sk(sk); struct sockaddr_alg *sa = (void *)uaddr; @@ -158,6 +158,10 @@ static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) void *private; int err; + /* If caller uses non-allowed flag, return error. */ + if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed)) + return -EINVAL; + if (sock->state == SS_CONNECTED) return -EINVAL; @@ -176,9 +180,7 @@ static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) if (IS_ERR(type)) return PTR_ERR(type); - private = type->bind(sa->salg_name, - sa->salg_feat & ~forbidden, - sa->salg_mask & ~forbidden); + private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask); if (IS_ERR(private)) { module_put(type->owner); return PTR_ERR(private); |