mirror of https://gitee.com/openkylin/linux.git
bpf: Prevent double bpf_prog_put call from bpf_tracing_prog_attach
The bpf_tracing_prog_attach error path calls bpf_prog_put
on prog, which causes refcount underflow when it's called
from link_create function.
link_create
prog = bpf_prog_get <-- get
...
tracing_bpf_link_attach(prog..
bpf_tracing_prog_attach(prog..
out_put_prog:
bpf_prog_put(prog); <-- put
if (ret < 0)
bpf_prog_put(prog); <-- put
Removing bpf_prog_put call from bpf_tracing_prog_attach
and making sure its callers call it instead.
Fixes: 4a1e7c0c63
("bpf: Support attaching freplace programs to multiple attach points")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210111191650.1241578-1-jolsa@kernel.org
This commit is contained in:
parent
f97844f9c5
commit
5541075a34
|
@ -2712,7 +2712,6 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog,
|
|||
out_put_prog:
|
||||
if (tgt_prog_fd && tgt_prog)
|
||||
bpf_prog_put(tgt_prog);
|
||||
bpf_prog_put(prog);
|
||||
return err;
|
||||
}
|
||||
|
||||
|
@ -2825,7 +2824,10 @@ static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
|
|||
tp_name = prog->aux->attach_func_name;
|
||||
break;
|
||||
}
|
||||
return bpf_tracing_prog_attach(prog, 0, 0);
|
||||
err = bpf_tracing_prog_attach(prog, 0, 0);
|
||||
if (err >= 0)
|
||||
return err;
|
||||
goto out_put_prog;
|
||||
case BPF_PROG_TYPE_RAW_TRACEPOINT:
|
||||
case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
|
||||
if (strncpy_from_user(buf,
|
||||
|
|
Loading…
Reference in New Issue