From be364c8c0f17a3dd42707b5a090b318028538eb9 Mon Sep 17 00:00:00 2001 From: Tommi Rantala Date: Tue, 27 Nov 2012 04:01:46 +0000 Subject: sctp: fix memory leak in sctp_datamsg_from_user() when copy from user space fails Trinity (the syscall fuzzer) discovered a memory leak in SCTP, reproducible e.g. with the sendto() syscall by passing invalid user space pointer in the second argument: #include #include #include int main(void) { int fd; struct sockaddr_in sa; fd = socket(AF_INET, SOCK_STREAM, 132 /*IPPROTO_SCTP*/); if (fd < 0) return 1; memset(&sa, 0, sizeof(sa)); sa.sin_family = AF_INET; sa.sin_addr.s_addr = inet_addr("127.0.0.1"); sa.sin_port = htons(11111); sendto(fd, NULL, 1, 0, (struct sockaddr *)&sa, sizeof(sa)); return 0; } As far as I can tell, the leak has been around since ~2003. Signed-off-by: Tommi Rantala Acked-by: Vlad Yasevich Signed-off-by: David S. Miller --- net/sctp/chunk.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'net/sctp') diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c index 7c2df9c33df3..f2aebdbb1eda 100644 --- a/net/sctp/chunk.c +++ b/net/sctp/chunk.c @@ -284,7 +284,7 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, goto errout; err = sctp_user_addto_chunk(chunk, offset, len, msgh->msg_iov); if (err < 0) - goto errout; + goto errout_chunk_free; offset += len; @@ -324,7 +324,7 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, __skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr - (__u8 *)chunk->skb->data); if (err < 0) - goto errout; + goto errout_chunk_free; sctp_datamsg_assign(msg, chunk); list_add_tail(&chunk->frag_list, &msg->chunks); @@ -332,6 +332,9 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, return msg; +errout_chunk_free: + sctp_chunk_free(chunk); + errout: list_for_each_safe(pos, temp, &msg->chunks) { list_del_init(pos); -- cgit v1.2.3 From 6e51fe7572590d8d86e93b547fab6693d305fd0d Mon Sep 17 00:00:00 2001 From: Tommi Rantala Date: Thu, 22 Nov 2012 03:23:16 +0000 Subject: sctp: fix -ENOMEM result with invalid user space pointer in sendto() syscall Consider the following program, that sets the second argument to the sendto() syscall incorrectly: #include #include #include int main(void) { int fd; struct sockaddr_in sa; fd = socket(AF_INET, SOCK_STREAM, 132 /*IPPROTO_SCTP*/); if (fd < 0) return 1; memset(&sa, 0, sizeof(sa)); sa.sin_family = AF_INET; sa.sin_addr.s_addr = inet_addr("127.0.0.1"); sa.sin_port = htons(11111); sendto(fd, NULL, 1, 0, (struct sockaddr *)&sa, sizeof(sa)); return 0; } We get -ENOMEM: $ strace -e sendto ./demo sendto(3, NULL, 1, 0, {sa_family=AF_INET, sin_port=htons(11111), sin_addr=inet_addr("127.0.0.1")}, 16) = -1 ENOMEM (Cannot allocate memory) Propagate the error code from sctp_user_addto_chunk(), so that we will tell user space what actually went wrong: $ strace -e sendto ./demo sendto(3, NULL, 1, 0, {sa_family=AF_INET, sin_port=htons(11111), sin_addr=inet_addr("127.0.0.1")}, 16) = -1 EFAULT (Bad address) Noticed while running Trinity (the syscall fuzzer). Signed-off-by: Tommi Rantala Acked-by: Vlad Yasevich Acked-by: Neil Horman Signed-off-by: David S. Miller --- net/sctp/chunk.c | 13 +++++++++---- net/sctp/socket.c | 4 ++-- 2 files changed, 11 insertions(+), 6 deletions(-) (limited to 'net/sctp') diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c index f2aebdbb1eda..69ce21e3716f 100644 --- a/net/sctp/chunk.c +++ b/net/sctp/chunk.c @@ -183,7 +183,7 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, msg = sctp_datamsg_new(GFP_KERNEL); if (!msg) - return NULL; + return ERR_PTR(-ENOMEM); /* Note: Calculate this outside of the loop, so that all fragments * have the same expiration. @@ -280,8 +280,11 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag, 0); - if (!chunk) + if (!chunk) { + err = -ENOMEM; goto errout; + } + err = sctp_user_addto_chunk(chunk, offset, len, msgh->msg_iov); if (err < 0) goto errout_chunk_free; @@ -315,8 +318,10 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, chunk = sctp_make_datafrag_empty(asoc, sinfo, over, frag, 0); - if (!chunk) + if (!chunk) { + err = -ENOMEM; goto errout; + } err = sctp_user_addto_chunk(chunk, offset, over,msgh->msg_iov); @@ -342,7 +347,7 @@ errout: sctp_chunk_free(chunk); } sctp_datamsg_put(msg); - return NULL; + return ERR_PTR(err); } /* Check whether this message has expired. */ diff --git a/net/sctp/socket.c b/net/sctp/socket.c index a60d1f8b41c5..406d957d08fb 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -1915,8 +1915,8 @@ SCTP_STATIC int sctp_sendmsg(struct kiocb *iocb, struct sock *sk, /* Break the message into multiple chunks of maximum size. */ datamsg = sctp_datamsg_from_user(asoc, sinfo, msg, msg_len); - if (!datamsg) { - err = -ENOMEM; + if (IS_ERR(datamsg)) { + err = PTR_ERR(datamsg); goto out_free; } -- cgit v1.2.3 From 92d64c261e77cb2a6117887617e2a629fea6b67c Mon Sep 17 00:00:00 2001 From: Schoch Christian Date: Wed, 28 Nov 2012 05:18:29 +0000 Subject: sctp: Error in calculation of RTTvar The calculation of RTTVAR involves the subtraction of two unsigned numbers which may causes rollover and results in very high values of RTTVAR when RTT > SRTT. With this patch it is possible to set RTOmin = 1 to get the minimum of RTO at 4 times the clock granularity. Change Notes: v2) *Replaced abs() by abs64() and long by __s64, changed patch description. Signed-off-by: Christian Schoch CC: Vlad Yasevich CC: Sridhar Samudrala CC: Neil Horman CC: linux-sctp@vger.kernel.org Acked-by: Vlad Yasevich Acked-by: Neil Horman Signed-off-by: David S. Miller --- net/sctp/transport.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/sctp') diff --git a/net/sctp/transport.c b/net/sctp/transport.c index 953c21e4af97..206cf5238fd3 100644 --- a/net/sctp/transport.c +++ b/net/sctp/transport.c @@ -331,7 +331,7 @@ void sctp_transport_update_rto(struct sctp_transport *tp, __u32 rtt) * 1/8, rto_alpha would be expressed as 3. */ tp->rttvar = tp->rttvar - (tp->rttvar >> net->sctp.rto_beta) - + ((abs(tp->srtt - rtt)) >> net->sctp.rto_beta); + + (((__u32)abs64((__s64)tp->srtt - (__s64)rtt)) >> net->sctp.rto_beta); tp->srtt = tp->srtt - (tp->srtt >> net->sctp.rto_alpha) + (rtt >> net->sctp.rto_alpha); } else { -- cgit v1.2.3