From ebf233fd40bfc70e53ac9ba6b46ec7b3439c3da1 Mon Sep 17 00:00:00 2001 From: Peng Sun Date: Wed, 27 Feb 2019 22:36:25 +0800 Subject: [PATCH] bpf: drop refcount if bpf_map_new_fd() fails in map_create() [ Upstream commit 352d20d611414715353ee65fc206ee57ab1a6984 ] In bpf/syscall.c, map_create() first set map->usercnt to 1, a file descriptor is supposed to return to userspace. When bpf_map_new_fd() fails, drop the refcount. Fixes: bd5f5f4ecb78 ("bpf: Add BPF_MAP_GET_FD_BY_ID") Signed-off-by: Peng Sun Acked-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin --- kernel/bpf/syscall.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 34110450a78f..f5c1d5479ba3 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -348,12 +348,12 @@ static int map_create(union bpf_attr *attr) err = bpf_map_new_fd(map); if (err < 0) { /* failed to allocate fd. - * bpf_map_put() is needed because the above + * bpf_map_put_with_uref() is needed because the above * bpf_map_alloc_id() has published the map * to the userspace and the userspace may * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID. */ - bpf_map_put(map); + bpf_map_put_with_uref(map); return err; } -- 2.20.1