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authorTommi Rantala <tt.rantala@gmail.com>2012-11-22 03:23:16 (GMT)
committerDavid S. Miller <davem@davemloft.net>2012-11-28 16:11:17 (GMT)
commit6e51fe7572590d8d86e93b547fab6693d305fd0d (patch)
tree381db27662cc48be7b1ae0b2fcb1e13e0da72e8f
parentbe364c8c0f17a3dd42707b5a090b318028538eb9 (diff)
downloadlinux-6e51fe7572590d8d86e93b547fab6693d305fd0d.tar.xz
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 <string.h> #include <arpa/inet.h> #include <sys/socket.h> 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 <tt.rantala@gmail.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/sctp/chunk.c13
-rw-r--r--net/sctp/socket.c4
2 files changed, 11 insertions, 6 deletions
diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c
index f2aebdb..69ce21e 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 a60d1f8..406d957 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;
}