[v2,2/4] CVE-2022-23219: Buffer overflow in sunrpc clnt_create for "unix" (bug 22542)

Message ID aafa82f116bad4d781e66751177cdd4995eb7c07.1642148513.git.fweimer@redhat.com
State New
Headers show
Series
  • CVE-2022-23218, CVE-2022-23219: sunrpc buffer overflows
Related show

Commit Message

Adhemerval Zanella via Libc-alpha Jan. 14, 2022, 8:24 a.m.
Processing an overlong pathname in the sunrpc clnt_create function
results in a stack-based buffer overflow.
---
 NEWS              |  4 +++-
 sunrpc/clnt_gen.c | 10 +++++++---
 2 files changed, 10 insertions(+), 4 deletions(-)

-- 
2.34.1

Comments

Siddhesh Poyarekar Jan. 17, 2022, 3:29 a.m. | #1
On 14/01/2022 13:54, Florian Weimer via Libc-alpha wrote:
> Processing an overlong pathname in the sunrpc clnt_create function

> results in a stack-based buffer overflow.

> ---

>   NEWS              |  4 +++-

>   sunrpc/clnt_gen.c | 10 +++++++---

>   2 files changed, 10 insertions(+), 4 deletions(-)


LGTM.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>


> 

> diff --git a/NEWS b/NEWS

> index a957b19fdc..94248b580d 100644

> --- a/NEWS

> +++ b/NEWS

> @@ -150,7 +150,9 @@ Changes to build and runtime requirements:

>   

>   Security related changes:

>   

> -  [Add security related changes here]

> +  CVE-2022-23219: Passing an overlong file name to the clnt_create

> +  legacy function could result in a stack-based buffer overflow when

> +  using the "unix" protocol.  Reported by Martin Sebor.

>   

>   The following bugs are resolved with this release:

>   

> diff --git a/sunrpc/clnt_gen.c b/sunrpc/clnt_gen.c

> index 13ced8994e..b44357cd88 100644

> --- a/sunrpc/clnt_gen.c

> +++ b/sunrpc/clnt_gen.c

> @@ -57,9 +57,13 @@ clnt_create (const char *hostname, u_long prog, u_long vers,

>   

>     if (strcmp (proto, "unix") == 0)

>       {

> -      memset ((char *)&sun, 0, sizeof (sun));

> -      sun.sun_family = AF_UNIX;

> -      strcpy (sun.sun_path, hostname);

> +      if (__sockaddr_un_set (&sun, hostname) < 0)

> +	{

> +	  struct rpc_createerr *ce = &get_rpc_createerr ();

> +	  ce->cf_stat = RPC_SYSTEMERROR;

> +	  ce->cf_error.re_errno = errno;

> +	  return NULL;

> +	}

>         sock = RPC_ANYSOCK;

>         client = clntunix_create (&sun, prog, vers, &sock, 0, 0);

>         if (client == NULL)

Patch

diff --git a/NEWS b/NEWS
index a957b19fdc..94248b580d 100644
--- a/NEWS
+++ b/NEWS
@@ -150,7 +150,9 @@  Changes to build and runtime requirements:
 
 Security related changes:
 
-  [Add security related changes here]
+  CVE-2022-23219: Passing an overlong file name to the clnt_create
+  legacy function could result in a stack-based buffer overflow when
+  using the "unix" protocol.  Reported by Martin Sebor.
 
 The following bugs are resolved with this release:
 
diff --git a/sunrpc/clnt_gen.c b/sunrpc/clnt_gen.c
index 13ced8994e..b44357cd88 100644
--- a/sunrpc/clnt_gen.c
+++ b/sunrpc/clnt_gen.c
@@ -57,9 +57,13 @@  clnt_create (const char *hostname, u_long prog, u_long vers,
 
   if (strcmp (proto, "unix") == 0)
     {
-      memset ((char *)&sun, 0, sizeof (sun));
-      sun.sun_family = AF_UNIX;
-      strcpy (sun.sun_path, hostname);
+      if (__sockaddr_un_set (&sun, hostname) < 0)
+	{
+	  struct rpc_createerr *ce = &get_rpc_createerr ();
+	  ce->cf_stat = RPC_SYSTEMERROR;
+	  ce->cf_error.re_errno = errno;
+	  return NULL;
+	}
       sock = RPC_ANYSOCK;
       client = clntunix_create (&sun, prog, vers, &sock, 0, 0);
       if (client == NULL)