ppp: Add upstream patch to fix bounds check in EAP code.

[people/pmueller/ipfire-2.x.git] / src / patches / ppp / ppp-2.4.8-pppd-fix-bounds-check-in-eap-code.patch

diff --git a/src/patches/ppp/ppp-2.4.8-pppd-fix-bounds-check-in-eap-code.patch b/src/patches/ppp/ppp-2.4.8-pppd-fix-bounds-check-in-eap-code.patch
new file mode 100644 (file)
index 0000000..858769f
--- /dev/null
+++ b/src/patches/ppp/ppp-2.4.8-pppd-fix-bounds-check-in-eap-code.patch
@@ -0,0 +1,35 @@
+commit 8d7970b8f3db727fe798b65f3377fe6787575426
+Author: Paul Mackerras <paulus@ozlabs.org>
+Date:   Mon Feb 3 15:53:28 2020 +1100
+
+    pppd: Fix bounds check in EAP code
+    
+    Given that we have just checked vallen < len, it can never be the case
+    that vallen >= len + sizeof(rhostname).  This fixes the check so we
+    actually avoid overflowing the rhostname array.
+    
+    Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
+    Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
+
+diff --git a/pppd/eap.c b/pppd/eap.c
+index 94407f5..1b93db0 100644
+--- a/pppd/eap.c
++++ b/pppd/eap.c
+@@ -1420,7 +1420,7 @@ int len;
+               }
+ 
+               /* Not so likely to happen. */
+-              if (vallen >= len + sizeof (rhostname)) {
++              if (len - vallen >= sizeof (rhostname)) {
+                       dbglog("EAP: trimming really long peer name down");
+                       BCOPY(inp + vallen, rhostname, sizeof (rhostname) - 1);
+                       rhostname[sizeof (rhostname) - 1] = '\0';
+@@ -1846,7 +1846,7 @@ int len;
+               }
+ 
+               /* Not so likely to happen. */
+-              if (vallen >= len + sizeof (rhostname)) {
++              if (len - vallen >= sizeof (rhostname)) {
+                       dbglog("EAP: trimming really long peer name down");
+                       BCOPY(inp + vallen, rhostname, sizeof (rhostname) - 1);
+                       rhostname[sizeof (rhostname) - 1] = '\0';