Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Peng Sun <sironhide0null@gmail.com>,
        Martin KaFai Lau <kafai@fb.com>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.14 142/209] bpf: decrease usercnt if bpf_map_new_fd() fails in bpf_map_get_fd_by_id()
Date:   Wed,  4 Dec 2019 18:55:54 +0100
Message-Id: <20191204175333.088896488@linuxfoundation.org>
In-Reply-To: <20191204175321.609072813@linuxfoundation.org>
References: <20191204175321.609072813@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Peng Sun <sironhide0null@gmail.com>

[ Upstream commit 781e62823cb81b972dc8652c1827205cda2ac9ac ]

In bpf/syscall.c, bpf_map_get_fd_by_id() use bpf_map_inc_not_zero()
to increase the refcount, both map->refcnt and map->usercnt. Then, if
bpf_map_new_fd() fails, should handle map->usercnt too.

Fixes: bd5f5f4ecb78 ("bpf: Add BPF_MAP_GET_FD_BY_ID")
Signed-off-by: Peng Sun <sironhide0null@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/bpf/syscall.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 59d2e94ecb798..34110450a78f2 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1354,7 +1354,7 @@ static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
 
 	fd = bpf_map_new_fd(map);
 	if (fd < 0)
-		bpf_map_put(map);
+		bpf_map_put_with_uref(map);
 
 	return fd;
 }
-- 
2.20.1