From 7011eca83afc313098f9869eea36742d4506bc02 Mon Sep 17 00:00:00 2001 From: Martin Lewis Date: Sun, 15 Sep 2019 18:51:30 +0200 Subject: [PATCH] replace: count_strstr - Handle an edge case where sub is empty If sub is empty, avoids an infinite loop. function old new delta count_strstr 45 63 +18 Signed-off-by: Martin Lewis Signed-off-by: Denys Vlasenko --- libbb/replace.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/libbb/replace.c b/libbb/replace.c index a661d96e6..6183d3e6f 100644 --- a/libbb/replace.c +++ b/libbb/replace.c @@ -15,6 +15,10 @@ unsigned FAST_FUNC count_strstr(const char *str, const char *sub) size_t sub_len = strlen(sub); unsigned count = 0; + /* If sub is empty, avoid an infinite loop */ + if (sub_len == 0) + return strlen(str) + 1; + while ((str = strstr(str, sub)) != NULL) { count++; str += sub_len; -- 2.25.1