From: Peng Sun sironhide0null@gmail.com
[ 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 sironhide0null@gmail.com Acked-by: Martin KaFai Lau kafai@fb.com Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Sasha Levin sashal@kernel.org --- 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 34110450a78f2..f5c1d5479ba3d 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; }