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[23.128.96.18]) by mx.google.com with ESMTP id w13si15469584edt.382.2020.04.18.07.43.14; Sat, 18 Apr 2020 07:43:36 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=fQBe63gI; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727943AbgDROlZ (ORCPT + 99 others); Sat, 18 Apr 2020 10:41:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:50406 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727899AbgDROlV (ORCPT ); Sat, 18 Apr 2020 10:41:21 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B0E1022262; Sat, 18 Apr 2020 14:41:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587220881; bh=zL0FdfL38x/EJDuy8U1yKqo4ejxmtZ5FfNqZxUFoe5I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fQBe63gIAcMOp6aqUwbq9mILaa8DHoE9tS9jNUywuNAt9AoJ6+C4k0bXuLpHjU/D9 /3B82mqC3ZLlFHotz1ccrDFOD0GIPqlbHVD7MqNFFWCu7i5IygybnU6OPukpeCHvyH Mxdzd19J/f+PPKpKCfGVD/k63PC4IqKCc57FTjg8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vasily Averin , Andrew Morton , Waiman Long , Davidlohr Bueso , Manfred Spraul , Al Viro , Ingo Molnar , NeilBrown , Peter Oberparleiter , Steven Rostedt , Linus Torvalds , Sasha Levin Subject: [PATCH AUTOSEL 5.4 26/78] ipc/util.c: sysvipc_find_ipc() should increase position index Date: Sat, 18 Apr 2020 10:39:55 -0400 Message-Id: <20200418144047.9013-26-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200418144047.9013-1-sashal@kernel.org> References: <20200418144047.9013-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vasily Averin [ Upstream commit 89163f93c6f969da5811af5377cc10173583123b ] If seq_file .next function does not change position index, read after some lseek can generate unexpected output. https://bugzilla.kernel.org/show_bug.cgi?id=206283 Signed-off-by: Vasily Averin Signed-off-by: Andrew Morton Acked-by: Waiman Long Cc: Davidlohr Bueso Cc: Manfred Spraul Cc: Al Viro Cc: Ingo Molnar Cc: NeilBrown Cc: Peter Oberparleiter Cc: Steven Rostedt Link: http://lkml.kernel.org/r/b7a20945-e315-8bb0-21e6-3875c14a8494@virtuozzo.com Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- ipc/util.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ipc/util.c b/ipc/util.c index d126d156efc64..594871610d454 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -764,13 +764,13 @@ static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos, total++; } + *new_pos = pos + 1; if (total >= ids->in_use) return NULL; for (; pos < ipc_mni; pos++) { ipc = idr_find(&ids->ipcs_idr, pos); if (ipc != NULL) { - *new_pos = pos + 1; rcu_read_lock(); ipc_lock_object(ipc); return ipc; -- 2.20.1