Commit be3bb83d authored by Hao Luo's avatar Hao Luo Committed by Alexei Starovoitov
Browse files

bpf, iter: Fix the condition on p when calling stop. 



In bpf_seq_read, seq->op->next() could return an ERR and jump to
the label stop. However, the existing code in stop does not handle
the case when p (returned from next()) is an ERR. Adds the handling
of ERR of p by converting p into an error and jumping to done.

Because all the current implementations do not have a case that
returns ERR from next(), so this patch doesn't have behavior changes
right now.

Acked-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarHao Luo <haoluo@google.com>
Link: https://lore.kernel.org/r/20220805214821.1058337-4-haoluo@google.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent f3a2aebd

kernel/bpf/bpf_iter.c

+5 −0
Original line number Diff line number Diff line
@@ -197,6 +197,11 @@ static ssize_t bpf_seq_read(struct file *file, char __user *buf, size_t size, 
	}

stop:

	offs = seq->count;

	if (IS_ERR(p)) {

		seq->op->stop(seq, NULL);

		err = PTR_ERR(p);

		goto done;

	}

	/* bpf program called if !p */

	seq->op->stop(seq, p);

	if (!p) {