[PATCH] tools:misc:xenlockprof: fix possible format string overflow

[PATCH] tools:misc:xenlockprof: fix possible format string overflow

[Seraphime Kirkovski]

GCC7 complains about a possible overflow/truncation in xenlockprof.

xenlockprof.c: In function ‘main’:
xenlockprof.c:100:53: error: ‘%s’ directive writing up to 39 bytes into a
                         region of size between 17 and 37 [-Werror=format-overflow=]
             sprintf(name, "unknown type(%d) %d lock %s", data[j].type,
                                                     ^~
xenlockprof.c:100:13: note: ‘sprintf’ output between 24 and 83 bytes
                                             into a destination of size 60
             sprintf(name, "unknown type(%d) %d lock %s", data[j].type,
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                     data[j].idx, data[j].name);
                     ~~~~~~~~~~~~~~~~~~~~~~~~~~

This increases the size of name to 100. Not the most scalable solution,
but certainly the "cheapest", as it doesn't add dependencies for
asprintf.

Signed-off-by: Seraphime Kirkovski <kirkseraph@gmail.com>
---
 tools/misc/xenlockprof.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/misc/xenlockprof.c b/tools/misc/xenlockprof.c
index 41fcb792cc..df23c82912 100644
--- a/tools/misc/xenlockprof.c
+++ b/tools/misc/xenlockprof.c
@@ -24,7 +24,7 @@ int main(int argc, char *argv[])
     uint32_t           i, j, n;
     uint64_t           time;
     double             l, b, sl, sb;
-    char               name[60];
+    char               name[100];
     DECLARE_HYPERCALL_BUFFER(xc_lockprof_data_t, data);
 
     if ( (argc > 2) || ((argc == 2) && (strcmp(argv[1], "-r") != 0)) )
-- 
2.11.0


_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel

Re: [PATCH] tools:misc:xenlockprof: fix possible format string overflow

[Wei Liu]

On Tue, Apr 04, 2017 at 07:31:59PM +0200, Seraphime Kirkovski wrote:
> GCC7 complains about a possible overflow/truncation in xenlockprof.
> 
> xenlockprof.c: In function ‘main’:
> xenlockprof.c:100:53: error: ‘%s’ directive writing up to 39 bytes into a
>                          region of size between 17 and 37 [-Werror=format-overflow=]
>              sprintf(name, "unknown type(%d) %d lock %s", data[j].type,
>                                                      ^~
> xenlockprof.c:100:13: note: ‘sprintf’ output between 24 and 83 bytes
>                                              into a destination of size 60
>              sprintf(name, "unknown type(%d) %d lock %s", data[j].type,
>              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>                      data[j].idx, data[j].name);
>                      ~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> This increases the size of name to 100. Not the most scalable solution,
> but certainly the "cheapest", as it doesn't add dependencies for
> asprintf.
> 
> Signed-off-by: Seraphime Kirkovski <kirkseraph@gmail.com>

Acked-by: Wei Liu <wei.liu2@citrix.com>

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel