From: Alex Gartrell <alexgartrell@gmail.com>
Date: Wed, 26 Aug 2020 07:55:49 +0000 (-0700)
Subject: libbpf: Fix unintentional success return code in bpf_object__load
X-Git-Tag: v5.8.17~454
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2b87f9ce106ed934e10e1e811304d49764790e08;p=thirdparty%2Fkernel%2Fstable.git

libbpf: Fix unintentional success return code in bpf_object__load

[ Upstream commit ef05afa66c59c2031a3798916ef3ff3778232129 ]

There are code paths where EINVAL is returned directly without setting
errno. In that case, errno could be 0, which would mask the
failure. For example, if a careless programmer set log_level to 10000
out of laziness, they would have to spend a long time trying to figure
out why.

Fixes: 4f33ddb4e3e2 ("libbpf: Propagate EPERM to caller on program load")
Signed-off-by: Alex Gartrell <alexgartrell@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200826075549.1858580-1-alexgartrell@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 236c91aff48f8..e4d304247c1ba 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -5253,7 +5253,7 @@ retry_load:
 		free(log_buf);
 		goto retry_load;
 	}
-	ret = -errno;
+	ret = errno ? -errno : -LIBBPF_ERRNO__LOAD;
 	cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
 	pr_warn("load bpf program failed: %s\n", cp);
 	pr_perm_msg(ret);