From 53909030aa29bffe1f8490df62176c2375135652 Mon Sep 17 00:00:00 2001
From: Quentin Monnet <quentin.monnet@netronome.com>
Date: Thu, 8 Nov 2018 11:52:25 +0000
Subject: tools: bpftool: prevent infinite loop in get_fdinfo()

Function getline() returns -1 on failure to read a line, thus creating
an infinite loop in get_fdinfo() if the key is not found. Fix it by
calling the function only as long as we get a strictly positive return
value.

Found by copying the code for a key which is not always present...

Fixes: 71bb428fe2c1 ("tools: bpf: add bpftool")
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 tools/bpf/bpftool/common.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'tools/bpf')

diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
index 25af85304ebe..e070b00ac309 100644
--- a/tools/bpf/bpftool/common.c
+++ b/tools/bpf/bpftool/common.c
@@ -304,7 +304,7 @@ char *get_fdinfo(int fd, const char *key)
 		return NULL;
 	}
 
-	while ((n = getline(&line, &line_n, fdi))) {
+	while ((n = getline(&line, &line_n, fdi)) > 0) {
 		char *value;
 		int len;
 
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