From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0CE84749E for ; Thu, 12 Jan 2023 14:15:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5F613C433F0; Thu, 12 Jan 2023 14:15:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673532923; bh=vZ14m4/QgwBJC8gK1vviGziQL8UQHKp9kHFX61E02jw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HkUNWELlLsTeWiAb65BEkJvbbIUcsE6DRONb58zQBpa1blihgwtX0FUzHp4ecn6pq olKbI5U/0WgbsVUp4wm2nSvzKmxQKB3sy7gQLLsyfgts7br9vGEpk9VwUrJMBXyJVb u2fWk4Y1B1oiyEjBiGhpP2y2lw25479U0z660pSw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Daniel Jordan , Herbert Xu , Sasha Levin Subject: [PATCH 5.10 315/783] padata: Fix list iterator in padata_do_serial() Date: Thu, 12 Jan 2023 14:50:31 +0100 Message-Id: <20230112135538.932239355@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230112135524.143670746@linuxfoundation.org> References: <20230112135524.143670746@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Daniel Jordan [ Upstream commit 57ddfecc72a6c9941d159543e1c0c0a74fe9afdd ] list_for_each_entry_reverse() assumes that the iterated list is nonempty and that every list_head is embedded in the same type, but its use in padata_do_serial() breaks both rules. This doesn't cause any issues now because padata_priv and padata_list happen to have their list fields at the same offset, but we really shouldn't be relying on that. Fixes: bfde23ce200e ("padata: unbind parallel jobs from specific CPUs") Signed-off-by: Daniel Jordan Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin --- kernel/padata.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/padata.c b/kernel/padata.c index 4d31a69a9b38..11ca3ebd8b12 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -403,13 +403,16 @@ void padata_do_serial(struct padata_priv *padata) int hashed_cpu = padata_cpu_hash(pd, padata->seq_nr); struct padata_list *reorder = per_cpu_ptr(pd->reorder_list, hashed_cpu); struct padata_priv *cur; + struct list_head *pos; spin_lock(&reorder->lock); /* Sort in ascending order of sequence number. */ - list_for_each_entry_reverse(cur, &reorder->list, list) + list_for_each_prev(pos, &reorder->list) { + cur = list_entry(pos, struct padata_priv, list); if (cur->seq_nr < padata->seq_nr) break; - list_add(&padata->list, &cur->list); + } + list_add(&padata->list, pos); spin_unlock(&reorder->lock); /* -- 2.35.1