From: Peng Sun <sironhide0null@gmail.com>
Date: Tue, 26 Feb 2019 14:15:37 +0000 (+0800)
Subject: bpf: decrease usercnt if bpf_map_new_fd() fails in bpf_map_get_fd_by_id()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=929ce038556398617480aca256c6cc92f87d859e;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

bpf: decrease usercnt if bpf_map_new_fd() fails in bpf_map_get_fd_by_id()

[ 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>
---

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index ea7300fa0c22..d411bca27b4f 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1483,7 +1483,7 @@ static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
 
 	fd = bpf_map_new_fd(map, f_flags);
 	if (fd < 0)
-		bpf_map_put(map);
+		bpf_map_put_with_uref(map);
 
 	return fd;
 }