commit 141b197408ab398c4f474ac1a728ab316e921f2b
author Prasad J Pandit <pjp@fedoraproject.org> Wed Jun 13 11:46:57 2018 +0530
committer Michael Roth <mdroth@linux.vnet.ibm.com> Tue Jul 03 10:58:06 2018 -0500
tree 524055e648e01ad0e02cee0c6f1d1fe855a771bb
parent 65650f0182c11a000d488a3b8e8e6ad071853f31

qga: check bytes count read by guest-file-read

While reading file content via 'guest-file-read' command,
'qmp_guest_file_read' routine allocates buffer of count+1
bytes. It could overflow for large values of 'count'.
Add check to avoid it.

Reported-by: Fakhri Zulkifli <mohdfakhrizulkifli@gmail.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Cc: qemu-stable@nongnu.org
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

qga/commands-posix.c

diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index 594d21e..9284e71 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -458,7 +458,7 @@
 
     if (!has_count) {
         count = QGA_READ_COUNT_DEFAULT;
-    } else if (count < 0) {
+    } else if (count < 0 || count >= UINT32_MAX) {
         error_setg(errp, "value '%" PRId64 "' is invalid for argument count",
                    count);
         return NULL;

qga/commands-win32.c

diff --git a/qga/commands-win32.c b/qga/commands-win32.c
index 70ee537..73f31fa 100644
--- a/qga/commands-win32.c
+++ b/qga/commands-win32.c
@@ -318,7 +318,7 @@
     }
     if (!has_count) {
         count = QGA_READ_COUNT_DEFAULT;
-    } else if (count < 0) {
+    } else if (count < 0 || count >= UINT32_MAX) {
         error_setg(errp, "value '%" PRId64
                    "' is invalid for argument count", count);
         return NULL;