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-rw-r--r--main/ppp/fix-bound-check-eap.patch40
1 files changed, 40 insertions, 0 deletions
diff --git a/main/ppp/fix-bound-check-eap.patch b/main/ppp/fix-bound-check-eap.patch
new file mode 100644
index 00000000000..746eb70961a
--- /dev/null
+++ b/main/ppp/fix-bound-check-eap.patch
@@ -0,0 +1,40 @@
+From 8d7970b8f3db727fe798b65f3377fe6787575426 Mon Sep 17 00:00:00 2001
+From: Paul Mackerras <paulus@ozlabs.org>
+Date: Mon, 3 Feb 2020 15:53:28 +1100
+Subject: [PATCH] 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>
+---
+ pppd/eap.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+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';
+--
+2.25.0
+