From: Hao Luo Date: Fri, 5 Aug 2022 21:48:16 +0000 (-0700) Subject: bpf, iter: Fix the condition on p when calling stop. X-Git-Tag: v6.1-rc5~319^2~407^2~30 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=be3bb83dab2df838cd9e681e3e9dcde87bfe4f95;p=platform%2Fkernel%2Flinux-starfive.git 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: Yonghong Song Signed-off-by: Hao Luo Link: https://lore.kernel.org/r/20220805214821.1058337-4-haoluo@google.com Signed-off-by: Alexei Starovoitov --- diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c index 2726a59..4b112aa 100644 --- a/kernel/bpf/bpf_iter.c +++ b/kernel/bpf/bpf_iter.c @@ -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) {