diff options
| author | Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> | 2018-01-08 19:02:28 -0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-01-10 14:53:22 -0500 |
| commit | 5960cefab9df76600a1a7d4ff592c59e14616e88 (patch) | |
| tree | f7fe350ca04f5ebb6ffa9d7fa09fcc822641c4a1 | |
| parent | 2e83acb970684008baee471427270c029a76ddbd (diff) | |
sctp: add a ceiling to optlen in some sockopts
Hangbin Liu reported that some sockopt calls could cause the kernel to log
a warning on memory allocation failure if the user supplied a large optlen
value. That is because some of them called memdup_user() without a ceiling
on optlen, allowing it to try to allocate really large buffers.
This patch adds a ceiling by limiting optlen to the maximum allowed that
would still make sense for these sockopt.
Reported-by: Hangbin Liu <haliu@redhat.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/sctp/socket.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 54c046783a89..022b94f11fd8 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -3498,6 +3498,8 @@ static int sctp_setsockopt_hmac_ident(struct sock *sk, if (optlen < sizeof(struct sctp_hmacalgo)) return -EINVAL; + optlen = min_t(unsigned int, optlen, sizeof(struct sctp_hmacalgo) + + SCTP_AUTH_NUM_HMACS * sizeof(u16)); hmacs = memdup_user(optval, optlen); if (IS_ERR(hmacs)) @@ -3536,6 +3538,11 @@ static int sctp_setsockopt_auth_key(struct sock *sk, if (optlen <= sizeof(struct sctp_authkey)) return -EINVAL; + /* authkey->sca_keylength is u16, so optlen can't be bigger than + * this. + */ + optlen = min_t(unsigned int, optlen, USHRT_MAX + + sizeof(struct sctp_authkey)); authkey = memdup_user(optval, optlen); if (IS_ERR(authkey)) @@ -3893,6 +3900,9 @@ static int sctp_setsockopt_reset_streams(struct sock *sk, if (optlen < sizeof(*params)) return -EINVAL; + /* srs_number_streams is u16, so optlen can't be bigger than this. */ + optlen = min_t(unsigned int, optlen, USHRT_MAX + + sizeof(__u16) * sizeof(*params)); params = memdup_user(optval, optlen); if (IS_ERR(params)) |