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 7D8E82505A9; Tue, 20 May 2025 14:11:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747750309; cv=none; b=tgOWTjuyy1jNZsNzE9xSvBywBlxXMWxWJDDg2K3lGki2VB0mpY4U4BQOpDDU31AIMkMPlOJDT7k2Z4LQRCrumZjcSwflGjORipmge9KchdzBgzxJfbs9uziHpa65HrInxOAUHi9xnP/ipiaEwFXksSL4QgHuNVBqUpEdX0nyGD0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747750309; c=relaxed/simple; bh=yRssfUquttrLNr9CSC/t1q9st3M3aLhuDPcVvHnaKHk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dWopGfLbzYKwxlQQogr3Bjg4S6WN9nLVnkQgV7DBVjZguzNEPThstvsCBuE3d7CRhJQtokqNKxrOgJy9psdmJi7JweFqRp2XST9cwpwRnRY4YurWajvfZ80vEjYPHJNafV1oBg3Uxmq5iFdw0mL0plKgPjeV7OtA7MnnchDyrr0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ax9dIF31; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ax9dIF31" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E3B91C4CEEA; Tue, 20 May 2025 14:11:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1747750309; bh=yRssfUquttrLNr9CSC/t1q9st3M3aLhuDPcVvHnaKHk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ax9dIF31HneZSNsn4icBCugq/vG2nCQU3rOnKvh5rL4ETYGPsxUrFuvm4dgd0gvUi VNgMRFZo893YftN5jiduj4AnQjzBDuLNtNjETv1CcluKR8OfwsIMcOze78Kl0/nmEx mrumloMckRLfYb0vikM6IIml5WtbtQmgOs9Dy+60= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tejun Heo , Andrea Righi Subject: [PATCH 6.12 070/143] sched_ext: bpf_iter_scx_dsq_new() should always initialize iterator Date: Tue, 20 May 2025 15:50:25 +0200 Message-ID: <20250520125812.819841965@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250520125810.036375422@linuxfoundation.org> References: <20250520125810.036375422@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tejun Heo commit 428dc9fc0873989d73918d4a9cc22745b7bbc799 upstream. BPF programs may call next() and destroy() on BPF iterators even after new() returns an error value (e.g. bpf_for_each() macro ignores error returns from new()). bpf_iter_scx_dsq_new() could leave the iterator in an uninitialized state after an error return causing bpf_iter_scx_dsq_next() to dereference garbage data. Make bpf_iter_scx_dsq_new() always clear $kit->dsq so that next() and destroy() become noops. Signed-off-by: Tejun Heo Fixes: 650ba21b131e ("sched_ext: Implement DSQ iterator") Cc: stable@vger.kernel.org # v6.12+ Acked-by: Andrea Righi Signed-off-by: Greg Kroah-Hartman --- kernel/sched/ext.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -6731,6 +6731,12 @@ __bpf_kfunc int bpf_iter_scx_dsq_new(str BUILD_BUG_ON(__alignof__(struct bpf_iter_scx_dsq_kern) != __alignof__(struct bpf_iter_scx_dsq)); + /* + * next() and destroy() will be called regardless of the return value. + * Always clear $kit->dsq. + */ + kit->dsq = NULL; + if (flags & ~__SCX_DSQ_ITER_USER_FLAGS) return -EINVAL;