This is a note to let you know that I've just added the patch titled

    sctp: fix -ENOMEM result with invalid user space pointer in sendto() syscall

to the 3.6-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     
sctp-fix-enomem-result-with-invalid-user-space-pointer-in-sendto-syscall.patch
and it can be found in the queue-3.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From cf64e7ab7564ea8dfc7a51e46261950ae2460abb Mon Sep 17 00:00:00 2001
From: Tommi Rantala <[email protected]>
Date: Thu, 22 Nov 2012 03:23:16 +0000
Subject: sctp: fix -ENOMEM result with invalid user space pointer in sendto() 
syscall


From: Tommi Rantala <[email protected]>

[ Upstream commit 6e51fe7572590d8d86e93b547fab6693d305fd0d ]

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 <[email protected]>
Acked-by: Vlad Yasevich <[email protected]>
Acked-by: Neil Horman <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 net/sctp/chunk.c  |   13 +++++++++----
 net/sctp/socket.c |    4 ++--
 2 files changed, 11 insertions(+), 6 deletions(-)

--- a/net/sctp/chunk.c
+++ b/net/sctp/chunk.c
@@ -183,7 +183,7 @@ struct sctp_datamsg *sctp_datamsg_from_u
 
        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_u
 
                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_u
 
                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. */
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1908,8 +1908,8 @@ SCTP_STATIC int sctp_sendmsg(struct kioc
 
        /* 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;
        }
 


Patches currently in stable-queue which might be from [email protected] are

queue-3.6/tmpfs-fix-shared-mempolicy-leak.patch
queue-3.6/sctp-fix-memory-leak-in-sctp_datamsg_from_user-when-copy-from-user-space-fails.patch
queue-3.6/sctp-fix-enomem-result-with-invalid-user-space-pointer-in-sendto-syscall.patch
--
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