From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f228.google.com (mail-yw1-f228.google.com [209.85.128.228]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 593E61E0DCB for ; Wed, 14 Jan 2026 20:47:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.228 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768423651; cv=none; b=glw9WdK3ecAAbsl9adfbfTi/CrLddSC8iwswUdeFyJ5/xpJZo6sUAScV5ZpmLKnwesGjxK3H4hKkmltB9jwjybP1zYVYXWufdXBEjbOAC7w7pFy4Zy5Ejhsoh/5NUQBORaoSFkjBleNQffj1EIg6w11EMqnD8NXHLz5C8xPIkDo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768423651; c=relaxed/simple; bh=1pW7O9UH3C0KS4RTlj2iVVMII/k9SWeXJzZS3nyoe10=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ARO3U9rUCXCdzAjvAV5Tf22Ogt37PdzxRqP2zW+QahtmRxh12Q8mg/xjWz97pahMteqhCzRFCwBD0TpcxXph8e4pGRAEy+cpnJ4gQ4c1EiAa9KHb4gmod/68IFcCJKSxhFjge3XE22LZ25vQU35MdLL0NPYOnhy035VFGUh6x6k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=purestorage.com; spf=fail smtp.mailfrom=purestorage.com; dkim=pass (2048-bit key) header.d=purestorage.com header.i=@purestorage.com header.b=J5MTcxV4; arc=none smtp.client-ip=209.85.128.228 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=purestorage.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=purestorage.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=purestorage.com header.i=@purestorage.com header.b="J5MTcxV4" Received: by mail-yw1-f228.google.com with SMTP id 00721157ae682-7926b269f03so1719677b3.2 for ; Wed, 14 Jan 2026 12:47:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=purestorage.com; s=google2022; t=1768423649; x=1769028449; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=TWLEQRO/UH0YKdM5ksbNTiP+oqc7ppfRc6exwkWZK9U=; b=J5MTcxV409kYTmONScMLdGdV1DAO2MhGVYWTZYGupWDn2s98O59L8nFkZ5YhDlUBms XzZ1aV/yMwzGUk4WTNyixVdauskD868RS2DvcoI/mqV4WCsgo3pdTM2Ktcc8XWH+/Rjn Puwi12NspHT3Cjp2QuaxySjMrLFb2LgIwRz3KZpE37fB7JLaYIynOvbbR4oO65VjBIA/ Db0sIlT4r0RsiKq6bbTKpVXfO8EzoL/xPft2nx6VdfG0GNqWrmi8Idd1Np5J8/dt0f2G JoYB+go5m/sHJSMM+4s2ROJ3fhlAgFvjOAG46XKvMlNmGSEYlOSbDee5ChjF1MsiGhqk 9yMA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768423649; x=1769028449; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=TWLEQRO/UH0YKdM5ksbNTiP+oqc7ppfRc6exwkWZK9U=; b=JbPJSZv4mgYu3PWd1Ze9jGOWsiZ92mTF3LBR7BhCExqXouXlHfcf5ieLqBj5YJsDn5 tAWq/tDKfK6vWy6LUM22Uu+Uvukjnf3wnmRIntfTxBFz7brjo9A3GpOswTw9SdXTAeXp vHB7WzsKqnVQSBdLusmfajcSl2STaBhEEVBU14dB/ioHnLf58z02ZKYKpJBJMlQGr0gs 1n7vfL2BfU0cs06gUqgAgxxZLJipkusoQJXj3XoF/oHJCLP9oIzKd8mCVw7Y2dQ072WV D7wdZvFEwNqPVlSzTzFiaJswvHEnTSQDZehAWyLAiM6ZihqsOLQG9STsub9dethfw/TR sQJA== X-Forwarded-Encrypted: i=1; AJvYcCW0uWxjNZXNogR177TgeG0CvV3tv/8v3r9FdRsRZwvnkcuIX5GaG8t6X/LeeaEGuG4AhFkNn9toCm3xsA==@vger.kernel.org X-Gm-Message-State: AOJu0YwKlS7SpPHK2+vzz4E1rj++CepOP4ROPz3HHKOFkTy2+eZ1X1RI cIbXMEGRRCz7xetEiTg70VPHq20LXK1SzQsGQ7z+VgjrWFV++3GVTo5bAcxj8QZchCmIAVmq45M OjY8Gn+P+ZioGMqAG9XupLLspbJmBu4LM8hZV X-Gm-Gg: AY/fxX7CNKWoanSAe1HmYloDEfGz8WXIP2WqHPwcRCJoSNABcepm4O3BsTwtsAJ2f6u MlqeQ4ou9LbbVNlQ+UcfnBHTuKNbt92vc5MuhRJ/fyU7nSaawFcZehzwIKtSyPxBGGGJICIgNVT aGtCtmCD3yDibNpA3dIdYoBivRuljTPHzYV5w5glgtC1YRE9tw6JPLbaZgizXWnpgAW2RAPiJvV 3fC+M8gm0w0i/NwG29FnrWU84KGwIpFcIiaaXVp6xjrOBX99NDNbFmdUQH/9PpVyopAG6EARLjR puuJLcp5OrK6Ws0RylsePMU4ik1T2s77H2C39BjHVgQXpWNfLXT/kc5AgFuu1gxAbrDleo+CTkH MRXoEh1F6TcZRbKbbIbrzVGfECRlxEmSAYsy9aj6vUA== X-Received: by 2002:a05:690c:18:b0:786:a774:e415 with SMTP id 00721157ae682-793a1d89a8bmr66756277b3.56.1768423649142; Wed, 14 Jan 2026 12:47:29 -0800 (PST) Received: from c7-smtp-2023.dev.purestorage.com ([208.88.159.129]) by smtp-relay.gmail.com with ESMTPS id 00721157ae682-790aa563f21sm18353387b3.4.2026.01.14.12.47.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Jan 2026 12:47:29 -0800 (PST) X-Relaying-Domain: purestorage.com Received: from dev-sconnor.dev.purestorage.com (unknown [IPv6:2620:125:9007:640:ffff::4936]) by c7-smtp-2023.dev.purestorage.com (Postfix) with ESMTP id 3269F3400AF; Wed, 14 Jan 2026 13:47:28 -0700 (MST) From: Seamus Connor To: Ming Lei , Jens Axboe , linux-block@vger.kernel.org Cc: Seamus Connor , Caleb Sander Mateos Subject: [PATCH v3] ublk: fix ublksrv pid handling for pid namespaces Date: Wed, 14 Jan 2026 12:47:04 -0800 Message-ID: <20260114204705.2249961-1-sconnor@purestorage.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260112225614.1817055-1-sconnor@purestorage.com> References: <20260112225614.1817055-1-sconnor@purestorage.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When ublksrv runs inside a pid namespace, START/END_RECOVERY compared the stored init-ns tgid against the userspace pid (getpid vnr), so the check failed and control ops could not proceed. Compare against the caller’s init-ns tgid and store that value, then translate it back to the caller’s pid namespace when reporting GET_DEV_INFO so ublk list shows a sensible pid. Testing: start/recover in a pid namespace; `ublk list` shows reasonable pid values in init, child, and sibling namespaces. Fixes: d37a224fc119 ("ublk: validate ublk server pid") Signed-off-by: Seamus Connor Reviewed-by: Caleb Sander Mateos --- Changes since v1: - Updated start_dev and end_recovery to respect the user-supplied pid Changes since v2: - Moved pid translation into a helper function drivers/block/ublk_drv.c | 35 ++++++++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 67d4a867aec4..01747d256ff5 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -2852,6 +2852,15 @@ static struct ublk_device *ublk_get_device_from_id(int idx) return ub; } +static pid_t ublk_translate_user_pid(pid_t ublksrv_pid) +{ + rcu_read_lock(); + ublksrv_pid = pid_nr(find_vpid(ublksrv_pid)); + rcu_read_unlock(); + + return ublksrv_pid; +} + static int ublk_ctrl_start_dev(struct ublk_device *ub, const struct ublksrv_ctrl_cmd *header) { @@ -2920,6 +2929,8 @@ static int ublk_ctrl_start_dev(struct ublk_device *ub, if (wait_for_completion_interruptible(&ub->completion) != 0) return -EINTR; + ublksrv_pid = ublk_translate_user_pid(ublksrv_pid); + if (ub->ublksrv_tgid != ublksrv_pid) return -EINVAL; @@ -3274,12 +3285,32 @@ static int ublk_ctrl_stop_dev(struct ublk_device *ub) static int ublk_ctrl_get_dev_info(struct ublk_device *ub, const struct ublksrv_ctrl_cmd *header) { + struct task_struct *p; + struct pid *pid; + struct ublksrv_ctrl_dev_info dev_info; + pid_t init_ublksrv_tgid = ub->dev_info.ublksrv_pid; void __user *argp = (void __user *)(unsigned long)header->addr; if (header->len < sizeof(struct ublksrv_ctrl_dev_info) || !header->addr) return -EINVAL; - if (copy_to_user(argp, &ub->dev_info, sizeof(ub->dev_info))) + memcpy(&dev_info, &ub->dev_info, sizeof(dev_info)); + dev_info.ublksrv_pid = -1; + + if (init_ublksrv_tgid > 0) { + rcu_read_lock(); + pid = find_pid_ns(init_ublksrv_tgid, &init_pid_ns); + p = pid_task(pid, PIDTYPE_TGID); + if (p) { + int vnr = task_tgid_vnr(p); + + if (vnr) + dev_info.ublksrv_pid = vnr; + } + rcu_read_unlock(); + } + + if (copy_to_user(argp, &dev_info, sizeof(dev_info))) return -EFAULT; return 0; @@ -3424,6 +3455,8 @@ static int ublk_ctrl_end_recovery(struct ublk_device *ub, pr_devel("%s: All FETCH_REQs received, dev id %d\n", __func__, header->dev_id); + ublksrv_pid = ublk_translate_user_pid(ublksrv_pid); + if (ub->ublksrv_tgid != ublksrv_pid) return -EINVAL; -- 2.43.0