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| author | Tommi Rantala <tt.rantala@gmail.com> | 2012-11-22 03:23:16 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-11-28 11:11:17 -0500 |
| commit | 6e51fe7572590d8d86e93b547fab6693d305fd0d (patch) | |
| tree | 381db27662cc48be7b1ae0b2fcb1e13e0da72e8f /net | |
| parent | be364c8c0f17a3dd42707b5a090b318028538eb9 (diff) | |
| download | linux-6e51fe7572590d8d86e93b547fab6693d305fd0d.tar.bz2 | |
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sctp/chunk.c | 13 | ||||
| -rw-r--r-- | net/sctp/socket.c | 4 |
2 files changed, 11 insertions, 6 deletions
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; } |