[PATCH] kernel/kexec.c: use vscnprintf() instead of vsnprintf() in vmcoreinfo_append_str()

[Chen Gang]

vsnprintf() may let 'r' larger than sizeof(buf), in this case, if 'r'
is also less than "vmcoreinfo_max_size - vmcoreinfo_size" (left size of
destination buffer), next memcpy() will read the unexpected addresses.

Signed-off-by: Chen Gang <gang.chen at asianux.com>
---
 kernel/kexec.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/kexec.c b/kernel/kexec.c
index 2a74f30..0abcd68 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1533,7 +1533,7 @@ void vmcoreinfo_append_str(const char *fmt, ...)
 	size_t r;
 
 	va_start(args, fmt);
-	r = vsnprintf(buf, sizeof(buf), fmt, args);
+	r = vscnprintf(buf, sizeof(buf), fmt, args);
 	va_end(args);
 
 	r = min(r, vmcoreinfo_max_size - vmcoreinfo_size);
-- 
1.7.7.6