From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.4]) (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 A74C537BE6F for ; Mon, 12 Oct 2026 02:11:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.4 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791771120; cv=none; b=OgWWFjqQ2pZ08fNPtAs4E5dAaZKZzFydaUPrPBVyHdS2rOaMkAVysOfB1jhi2MaCTNCPqaAHWkJVf8RMjYcadZZ1gBSTw/8/cgy9HKdI+20ovy/kcoBecUAjS9NZzx3HaZAhHf3vxam44dB9DgR4fmeYvuCDDQHg5v291H9YukE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791771120; c=relaxed/simple; bh=X+nPGg4WzuMTgqQVoSQy+Z7cH43dSDxPwSFrGFdfNAs=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=VoVLSTIgwQsJ+LJuxyt0hw17ZG8nDSpWHGRdLzB6aiOBEIRCwxwRP53vh4IeZ7YtxAMtC+QKPPI65iFtohpE8QyyiDitt7XNLGDoQdkgcVRJap0JJoe5y5e1Ll0CHShe107fCPs8sCvdREe+/tjgudKgH4USZge3XIs2QiyCxbI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=ecppsQ7A; arc=none smtp.client-ip=220.197.31.4 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="ecppsQ7A" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=9g 7RJTA1WWN395zTrCYTTEsBF3mUTfm7Ewrm8cQuOvY=; b=ecppsQ7AhG7JX955Au qP4z5gWfh6DRDq/WqrDmCws/s8gjw++7UigQWseH5DPGqTCqLL7D0Fg3sHQIkTkC wEUzD3gxUwvGISmEwgycwCc39UeP5K4EohCMO5HfuTdDtR3J/5HY2Y1y0sG2DL30 FGRXgrnJSaxm3P71ltu+SaPMg= Received: from localhost.localdomain (unknown []) by gzga-smtp-mtada-g0-4 (Coremail) with SMTP id _____wBHksPDQcxq9pjpDw--.11839S2; Mon, 12 Oct 2026 10:11:16 +0800 (CST) From: Rongguang Wei To: netdev@vger.kernel.org Cc: willemdebruijn.kernel@gmail.com, jasowangio@gmail.com, andrew+netdev@lunn.ch, davem@davemloft.net, Rongguang Wei Subject: [RESEND PATCH net v5 0/2] tun: fix re-attaching the socket filter Date: Mon, 12 Oct 2026 10:11:11 +0800 Message-Id: <20261012021113.45939-1-clementwei90@163.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:_____wBHksPDQcxq9pjpDw--.11839S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxAF43Xr1kuw1rCry7Aw1fZwb_yoW5WrW5pF WYg345tw4kWryxZ3Z3ZayxZ34Yyws7GFW3Zwn7Ga4rZws8Wryjv3yaga45ZasFyrZ7uw12 yF1YvwnIg3WDAaDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07jnhL8UUUUU= X-CM-SenderInfo: 5fohzv5qwzvxizq6il2tof0z/xtbC4QZPumrMQcadSQAA3n From: Rongguang Wei This is v5 of the series that fixes attaching a queue to a TAP device which re-installs the socket filter of a persistent device. Patch 1 keeps a copy of the program in the kernel when it is configured, instead of reading tun->fprog from user space again on every later attach, and fixes the inverted error check in tun_attach(). The two changes are one patch on purpose: with only the kernel copy every re-attach returns 0 without publishing the queue, and with only the check fixed a re-attach that used to succeed without a filter starts to fail. IFF_NOFILTER keeps working and is no longer needed as a workaround. Patch 2 adds selftests: it re-attaches a queue after the buffer the program was copied from was made unreadable, attaches a second queue from a fresh socket to check that the filter is rebuilt from the kernel copy, and checks that a rejected TUNATTACHFILTER keeps the saved program, plus the ways to attach a queue without a filter. Thanks to Willem de Bruijn for the reviews, and to the CI reviews for the comments they raised. Rongguang Wei (2): tun: keep a kernel copy of the socket filter program selftests: net: add TAP socket filter attach tests --- v5: - add kernel-doc for sk_attach_filter_kern() describing what the missing original program means for SO_GET_FILTER and sock_diag - mention in the message that a rejected header now leaves the installed filter alone - fix the wording of the mprotect() comment and note what the IFF_NOFILTER and TUNGETFILTER checks in the re-attach test v4: - merge the kernel copy and the error check into one patch, so that no step of the series turns a re-attach into a silent no-op or into a new failure - charge the kernel copy to the caller's memory cgroup - selftests: check that the queue is attached again, and attach a new queue to see that the filter was installed from the kernel copy v3: - reorder: the kernel copy of the program comes before the corrected error check - add sk_attach_filter_kern() in the patch that first uses it - address the review of the selftests v2: - roll back the filter attach when a later step of tun_attach() fails - keep a copy of the program in the kernel, so that a later attach does not depend on the address space of the process that set the filter - add selftests for the re-attach and for a rejected TUNATTACHFILTER v1: - https://lore.kernel.org/netdev/20260923025653.59348-1-clementwei90@163.com/ --- drivers/net/tun.c | 56 ++++++++- include/linux/filter.h | 1 + net/core/filter.c | 37 ++++++ tools/testing/selftests/net/tun.c | 197 ++++++++++++++++++++++++++++++ 4 files changed, 286 insertions(+), 5 deletions(-) base-commit: a5ebb76233b79db01e82e061173cb73c6d2b5c6b -- 2.25.1 No virus found Checked by Hillstone Network AntiVirus