From 05d887b4619e54a2b7d487ac1c31b4544ce58533 Mon Sep 17 00:00:00 2001 From: "xypron.glpk@gmx.de" Date: Wed, 3 May 2017 23:20:10 +0200 Subject: [PATCH] lib: circbuf: avoid possible null pointer dereference We should not first dereference p and afterwards assert that is was not NULL. Instead do the assert first. The problem was indicated by cppcheck. Signed-off-by: Heinrich Schuchardt --- lib/circbuf.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/lib/circbuf.c b/lib/circbuf.c index 9848da3b7b..6ed0516430 100644 --- a/lib/circbuf.c +++ b/lib/circbuf.c @@ -41,11 +41,13 @@ int buf_free (circbuf_t * buf) int buf_pop (circbuf_t * buf, char *dest, unsigned int len) { unsigned int i; - char *p = buf->top; + char *p; assert (buf != NULL); assert (dest != NULL); + p = buf->top; + /* Cap to number of bytes in buffer */ if (len > buf->size) len = buf->size; @@ -69,11 +71,13 @@ int buf_push (circbuf_t * buf, const char *src, unsigned int len) { /* NOTE: this function allows push to overwrite old data. */ unsigned int i; - char *p = buf->tail; + char *p; assert (buf != NULL); assert (src != NULL); + p = buf->tail; + for (i = 0; i < len; i++) { *p++ = src[i]; if (p == buf->end) { -- 2.25.1