[PATCH] kbuild: replace unbounded sprintf call in modpost

[Kees Cook]

The modpost tool could overflow its stack buffer if someone was running
with an insane shell environment. Regardless, it's technically a bug,
so this fixes it to truncate the string instead of seg-faulting.

Found by Coverity.

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 scripts/mod/sumversion.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/mod/sumversion.c b/scripts/mod/sumversion.c
index 9dfcd6d988da..deb2994b04c4 100644
--- a/scripts/mod/sumversion.c
+++ b/scripts/mod/sumversion.c
@@ -416,7 +416,7 @@ void get_src_version(const char *modname, char sum[], unsigned sumlen)
 		basename = strrchr(modname, '/') + 1;
 	else
 		basename = modname;
-	sprintf(filelist, "%s/%.*s.mod", modverdir,
+	snprintf(filelist, sizeof(filelist), "%s/%.*s.mod", modverdir,
 		(int) strlen(basename) - 2, basename);
 
 	file = grab_file(filelist, &len);
-- 
1.7.9.5


-- 
Kees Cook
Chrome OS Security
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