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authorMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>2018-01-08 19:02:28 -0200
committerDavid S. Miller <davem@davemloft.net>2018-01-10 14:53:22 -0500
commit5960cefab9df76600a1a7d4ff592c59e14616e88 (patch)
treef7fe350ca04f5ebb6ffa9d7fa09fcc822641c4a1
parent2e83acb970684008baee471427270c029a76ddbd (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.c10
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))