[patch 38/42] sunrpc: fix possible overrun on read of /proc/sys/sunrpc/transports

[patch 38/42] sunrpc: fix possible overrun on read of /proc/sys/sunrpc/transports

[Greg KH]

2.6.26-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Cyrill Gorcunov <gorcunov@gmail.com>

commit 27df6f25ff218072e0e879a96beeb398a79cdbc8 upstream

Vegard Nossum reported
----------------------
> I noticed that something weird is going on with /proc/sys/sunrpc/transports.
> This file is generated in net/sunrpc/sysctl.c, function proc_do_xprt(). When
> I "cat" this file, I get the expected output:
>    $ cat /proc/sys/sunrpc/transports
>    tcp 1048576
>    udp 32768

> But I think that it does not check the length of the buffer supplied by
> userspace to read(). With my original program, I found that the stack was
> being overwritten by the characters above, even when the length given to
> read() was just 1.

David Wagner added (among other things) that copy_to_user could be
probably used here.

Ingo Oeser suggested to use simple_read_from_buffer() here.

The conclusion is that proc_do_xprt doesn't check for userside buffer
size indeed so fix this by using Ingo's suggestion.

Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
CC: Ingo Oeser <ioe-lkml-MFZNYGWX9eyELgA04lAiVw@public.gmane.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Greg Banks <gnb@sgi.com>
Cc: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 net/sunrpc/sysctl.c |   18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)

--- a/net/sunrpc/sysctl.c
+++ b/net/sunrpc/sysctl.c
@@ -60,24 +60,14 @@ static int proc_do_xprt(ctl_table *table
 			void __user *buffer, size_t *lenp, loff_t *ppos)
 {
 	char tmpbuf[256];
-	int len;
+	size_t len;
+
 	if ((*ppos && !write) || !*lenp) {
 		*lenp = 0;
 		return 0;
 	}
-	if (write)
-		return -EINVAL;
-	else {
-		len = svc_print_xprts(tmpbuf, sizeof(tmpbuf));
-		if (!access_ok(VERIFY_WRITE, buffer, len))
-			return -EFAULT;
-
-		if (__copy_to_user(buffer, tmpbuf, len))
-			return -EFAULT;
-	}
-	*lenp -= len;
-	*ppos += len;
-	return 0;
+	len = svc_print_xprts(tmpbuf, sizeof(tmpbuf));
+	return simple_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len);
 }
 
 static int

-- 

[patch 39/42] nfsd: fix buffer overrun decoding NFSv4 acl

[Greg KH]

2.6.26-stable review patch.  If anyone has any objections, please let us know.

------------------

From: J. Bruce Fields <bfields@citi.umich.edu>

commit 91b80969ba466ba4b915a4a1d03add8c297add3f upstream

The array we kmalloc() here is not large enough.

Thanks to Johann Dahm and David Richter for bug report and testing.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: David Richter <richterd@citi.umich.edu>
Tested-by: Johann Dahm <jdahm@umich.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 fs/nfsd/nfs4acl.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/nfsd/nfs4acl.c
+++ b/fs/nfsd/nfs4acl.c
@@ -443,7 +443,7 @@ init_state(struct posix_acl_state *state
 	 * enough space for either:
 	 */
 	alloc = sizeof(struct posix_ace_state_array)
-		+ cnt*sizeof(struct posix_ace_state);
+		+ cnt*sizeof(struct posix_user_ace_state);
 	state->users = kzalloc(alloc, GFP_KERNEL);
 	if (!state->users)
 		return -ENOMEM;

--