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 633B83A63E8; Mon, 20 Apr 2026 13:26:40 +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=1776691600; cv=none; b=oz31HK4gGDQPcQ3QZkRKe5tZnkkHIeef7MWjeL7QbYYpNkkuadM+9egtbyzlWue2Oe7/ZPab63fSIi9TKHWtGL0aulddUv80iGudJYxkqiHr3gjuCBrj6JAnWfYDGQrUM8N7d5KlF6vOTsJq0rHwcmX6977XcdxN29li8USdQfs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776691600; c=relaxed/simple; bh=k43V/qSmU7C+NtBAQOUmZaioCpCS405F2aNaLv2Pv2c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cf6IxPwNYiZu1VSavpPdlopdquuH0ttpfpRLylX5l3Xzpc6M/2pTZixF+KGgWX9UpvafYuBjbC1gF5nYWnVKKQTJ64Dg4JS14G4DZDWa6MGICcSc7DLBEleFtFPla2C+np0Jv78m4mopkjXUXZ/RQZ4/fB++Bj/K9CRYjWZUULU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LKqZ9uDu; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LKqZ9uDu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 555A8C2BCB9; Mon, 20 Apr 2026 13:26:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776691600; bh=k43V/qSmU7C+NtBAQOUmZaioCpCS405F2aNaLv2Pv2c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LKqZ9uDu9W19ShroGAzPcXdARXWx2+j0DrkIFEgHsbXuL0+Fe2cZgKgREv+Lbdy6q xAiqN7rJYzyUFb+P+Mhef/Za35sh6rHHDXn13p7mPiPooGQgwmpzhQS9d1Wy5MsBzp 6EohYkWCurybDKJQwzxMe25YlKCfA0847+FRXOkSWL1OngCbyt+9vtp670g/wZKgLF 5g2vj49qmQHXiznZt5QB1IaMzPleN2lbMQu3PjutxFH5tIkdB910SiGY8WyBfHaJlD sMCNhP/siYg+/4NcMlN4ZN8mo2rUGyxlq1MPsvrYh9jiDb9WrHvv4ZG67NWf0MVC3o lMkaeeBolnreQ== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Jiexun Wang , Yifan Wu , Juefei Pu , Yuan Tan , Xin Liu , Ren Wei , Ren Wei , Kuniyuki Iwashima , Jakub Kicinski , Sasha Levin , davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, xemul@parallels.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH AUTOSEL 6.18] af_unix: read UNIX_DIAG_VFS data under unix_state_lock Date: Mon, 20 Apr 2026 09:18:38 -0400 Message-ID: <20260420132314.1023554-124-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260420132314.1023554-1-sashal@kernel.org> References: <20260420132314.1023554-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.18.23 Content-Transfer-Encoding: 8bit From: Jiexun Wang [ Upstream commit 39897df386376912d561d4946499379effa1e7ef ] Exact UNIX diag lookups hold a reference to the socket, but not to u->path. Meanwhile, unix_release_sock() clears u->path under unix_state_lock() and drops the path reference after unlocking. Read the inode and device numbers for UNIX_DIAG_VFS while holding unix_state_lock(), then emit the netlink attribute after dropping the lock. This keeps the VFS data stable while the reply is being built. Fixes: 5f7b0569460b ("unix_diag: Unix inode info NLA") Reported-by: Yifan Wu Reported-by: Juefei Pu Co-developed-by: Yuan Tan Signed-off-by: Yuan Tan Suggested-by: Xin Liu Tested-by: Ren Wei Signed-off-by: Jiexun Wang Signed-off-by: Ren Wei Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260407080015.1744197-1-n05ec@lzu.edu.cn Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- LLM Generated explanations, may be completely bogus: Error: Failed to generate final synthesis net/unix/diag.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/net/unix/diag.c b/net/unix/diag.c index ca34730261510..c9c1e51c44196 100644 --- a/net/unix/diag.c +++ b/net/unix/diag.c @@ -28,18 +28,23 @@ static int sk_diag_dump_name(struct sock *sk, struct sk_buff *nlskb) static int sk_diag_dump_vfs(struct sock *sk, struct sk_buff *nlskb) { - struct dentry *dentry = unix_sk(sk)->path.dentry; + struct unix_diag_vfs uv; + struct dentry *dentry; + bool have_vfs = false; + unix_state_lock(sk); + dentry = unix_sk(sk)->path.dentry; if (dentry) { - struct unix_diag_vfs uv = { - .udiag_vfs_ino = d_backing_inode(dentry)->i_ino, - .udiag_vfs_dev = dentry->d_sb->s_dev, - }; - - return nla_put(nlskb, UNIX_DIAG_VFS, sizeof(uv), &uv); + uv.udiag_vfs_ino = d_backing_inode(dentry)->i_ino; + uv.udiag_vfs_dev = dentry->d_sb->s_dev; + have_vfs = true; } + unix_state_unlock(sk); - return 0; + if (!have_vfs) + return 0; + + return nla_put(nlskb, UNIX_DIAG_VFS, sizeof(uv), &uv); } static int sk_diag_dump_peer(struct sock *sk, struct sk_buff *nlskb) -- 2.53.0