From: Prasad J Pandit <pjp@fedoraproject.org>

Date: Wed, 13 Jun 2018 11:46:57 +0530

Subject: [PATCH] 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>

(cherry picked from commit 141b197408ab398c4f474ac1a728ab316e921f2b)

---

 qga/commands-posix.c | 2 +-

 qga/commands-win32.c | 2 +-

 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/qga/commands-posix.c b/qga/commands-posix.c

index ab0c63d931..bcdb808fa3 100644

--- a/qga/commands-posix.c

+++ b/qga/commands-posix.c

@@ -457,7 +457,7 @@ struct GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count,

     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;

diff --git a/qga/commands-win32.c b/qga/commands-win32.c

index 619dbd2bc2..be6fa1a89e 100644

--- a/qga/commands-win32.c

+++ b/qga/commands-win32.c

@@ -315,7 +315,7 @@ GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count,

     }

     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;