[PATCH AUTOSEL 4.19 013/123] tools: bpftool: prevent infinite loop in get_fdinfo()
From: Sasha Levin <sashal@kernel.org>
Date: 2018-12-05 10:13:33
Also in:
lkml, stable
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [tooling] (bpftool), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Quentin Monnet, Linus Torvalds
From: Quentin Monnet <redacted>
[ Upstream commit 53909030aa29bffe1f8490df62176c2375135652 ]
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 <redacted>
Reviewed-by: Jakub Kicinski <redacted>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/bpf/bpftool/common.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
index b3a0709ea7ed..fcaf00621102 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;
--
2.17.1