diff mbox

[libdrm] xf86drm: fix null termination of string buffer

Message ID 20161213085535.31043-2-archer_ame@yahoo.co.jp (mailing list archive)
State New, archived
Headers show

Commit Message

archer_ame@yahoo.co.jp Dec. 13, 2016, 8:55 a.m. UTC 
From: Taro Yamada <archer_ame@yahoo.co.jp>

The string written to the buffer by read() is not null-terminated,
but currently drmParsePciBusInfo() places null character only at the end of the buffer, not at the end of the
string.
As a result, the string passed to sscanf() contains an uninitialized value.

This patch changes to places null character at the end of the string.

Signed-off-by: Taro Yamada <archer_ame@yahoo.co.jp>
---
 xf86drm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/xf86drm.c b/xf86drm.c
index b5eeeb0..a59cfd0 100644
--- a/xf86drm.c
+++ b/xf86drm.c
@@ -2925,11 +2925,11 @@  static int drmParsePciBusInfo(int maj, int min, drmPciBusInfoPtr info)
     if (fd < 0)
         return -errno;
 
-    ret = read(fd, data, sizeof(data));
-    data[sizeof(data)-1] = '\0';
+    ret = read(fd, data, sizeof(data)-1);
     close(fd);
     if (ret < 0)
         return -errno;
+    data[ret] = '\0';
 
 #define TAG "PCI_SLOT_NAME="
     str = strstr(data, TAG);