From 2e83acb970684008baee471427270c029a76ddbd Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Mon, 8 Jan 2018 19:02:27 -0200 Subject: [PATCH 1/3] sctp: GFP_ATOMIC is not needed in sctp_setsockopt_events So replace it with GFP_USER and also add __GFP_NOWARN. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/sctp/socket.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index b4fb6e4886d2..54c046783a89 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -2277,7 +2277,7 @@ static int sctp_setsockopt_events(struct sock *sk, char __user *optval, if (asoc && sctp_outq_is_empty(&asoc->outqueue)) { event = sctp_ulpevent_make_sender_dry_event(asoc, - GFP_ATOMIC); + GFP_USER | __GFP_NOWARN); if (!event) return -ENOMEM; From 5960cefab9df76600a1a7d4ff592c59e14616e88 Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Mon, 8 Jan 2018 19:02:28 -0200 Subject: [PATCH 2/3] 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 Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/sctp/socket.c | 10 ++++++++++ 1 file changed, 10 insertions(+) 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)) From c76f97c99ae6d26d14c7f0e50e074382bfbc9f98 Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Mon, 8 Jan 2018 19:02:29 -0200 Subject: [PATCH 3/3] sctp: make use of pre-calculated len Some sockopt handling functions were calculating the length of the buffer to be written to userspace and then calculating it again when actually writing the buffer, which could lead to some write not using an up-to-date length. This patch updates such places to just make use of the len variable. Also, replace some sizeof(type) to sizeof(var). Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/sctp/socket.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 022b94f11fd8..9b01e994f661 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -5025,7 +5025,7 @@ static int sctp_getsockopt_autoclose(struct sock *sk, int len, char __user *optv len = sizeof(int); if (put_user(len, optlen)) return -EFAULT; - if (copy_to_user(optval, &sctp_sk(sk)->autoclose, sizeof(int))) + if (copy_to_user(optval, &sctp_sk(sk)->autoclose, len)) return -EFAULT; return 0; } @@ -5655,6 +5655,9 @@ copy_getaddrs: err = -EFAULT; goto out; } + /* XXX: We should have accounted for sizeof(struct sctp_getaddrs) too, + * but we can't change it anymore. + */ if (put_user(bytes_copied, optlen)) err = -EFAULT; out: @@ -6091,7 +6094,7 @@ static int sctp_getsockopt_maxseg(struct sock *sk, int len, params.assoc_id = 0; } else if (len >= sizeof(struct sctp_assoc_value)) { len = sizeof(struct sctp_assoc_value); - if (copy_from_user(¶ms, optval, sizeof(params))) + if (copy_from_user(¶ms, optval, len)) return -EFAULT; } else return -EINVAL; @@ -6261,7 +6264,9 @@ static int sctp_getsockopt_active_key(struct sock *sk, int len, if (len < sizeof(struct sctp_authkeyid)) return -EINVAL; - if (copy_from_user(&val, optval, sizeof(struct sctp_authkeyid))) + + len = sizeof(struct sctp_authkeyid); + if (copy_from_user(&val, optval, len)) return -EFAULT; asoc = sctp_id2assoc(sk, val.scact_assoc_id); @@ -6273,7 +6278,6 @@ static int sctp_getsockopt_active_key(struct sock *sk, int len, else val.scact_keynumber = ep->active_key_id; - len = sizeof(struct sctp_authkeyid); if (put_user(len, optlen)) return -EFAULT; if (copy_to_user(optval, &val, len)) @@ -6299,7 +6303,7 @@ static int sctp_getsockopt_peer_auth_chunks(struct sock *sk, int len, if (len < sizeof(struct sctp_authchunks)) return -EINVAL; - if (copy_from_user(&val, optval, sizeof(struct sctp_authchunks))) + if (copy_from_user(&val, optval, sizeof(val))) return -EFAULT; to = p->gauth_chunks; @@ -6344,7 +6348,7 @@ static int sctp_getsockopt_local_auth_chunks(struct sock *sk, int len, if (len < sizeof(struct sctp_authchunks)) return -EINVAL; - if (copy_from_user(&val, optval, sizeof(struct sctp_authchunks))) + if (copy_from_user(&val, optval, sizeof(val))) return -EFAULT; to = p->gauth_chunks;