From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 1136C2868AB for ; Fri, 11 Sep 2026 00:29:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789086565; cv=none; b=oAucfTcNqVbLNmiS4iyjKgPpxqRqPCmeEKfmMrmWXtlrQhF7ozpcqUd/zpCiwmRQcbCLwnsq32e7xqCXICqECe8KuixKCo+ZTaS6prBEyINaChBxUOTzIzT0aZcN9gEEIW7erNUQcDsmEQaXdCYR+aLNVw+fHydzpKl5SOCiRBM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789086565; c=relaxed/simple; bh=D47f05Tgu8d9YUjj9oEphIe3EXSUy64XqA8XPLZmC6c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=R6veCoHF67eJp5tiuCjDMlmjQYU2nc6yXxLVn/0miFjuc1bBh+PXWLMELCfodZZ7FORh4xU35T2XzydK4Hu4VfGm2ympzR/AAqTuYVaVQa04a+HyI0mjSt9LEyAkTuJHt1gKD4ZXZV/QOxvIHBNe/gnbNQI7e/TlDGABbeCS4Jo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PjepOPfO; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="PjepOPfO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9B5B61F000FF; Fri, 11 Sep 2026 00:29:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789086563; bh=iTDQkFSbRDfNf9mqrdGKpi3yufAiwK44zrc2slI/VD8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=PjepOPfOM98Mvtg8lYo0nJnUgBCY/yLZhQVFs5ZXbdVlTbS3t4EkVS6pCb9QN5XLa Yr9wwUfEYyACb6T4bBQvLFuDeqIGkTd9kvN+t2DBjOdsOQkqxOmQcDd0EGrDgbMWGQ 0GehU8lWVnD4COxZzcfBdTWALJqgYnBL+0RhpoO5jphOAIC23Zo11bK7UY7rjOG+oa r+SA9qus/rDmA861ZCEoomsDXJ4kVrAFTMT8en0lM0M0tpFrnzVp9gNjZtQirseq1y K/HS/YkUmoxY96bXTjRh1hZbbQb6zg9LPgsaKvy3u8bmqkrez3WleMKoGOJp1xZs4t 1j5A5PeAjDTKg== From: Sasha Levin To: stable@vger.kernel.org Cc: Tristan Madani , Sagi Grimberg , John Garry , Christoph Hellwig , Keith Busch , Sasha Levin Subject: [PATCH 5.15.y] nvme: add missing SRCU grace period in error path Date: Thu, 10 Sep 2026 20:29:20 -0400 Message-ID: <20260911002920.3427959-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026090941-alumni-snare-26ce@gregkh> References: <2026090941-alumni-snare-26ce@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Tristan Madani [ Upstream commit ef248d5de4469fb6bbaf8dbe0c4c47800080d648 ] nvme_alloc_ns() error path at out_unlink_ns removes ns from the namespace head siblings list with list_del_rcu(&ns->siblings) but does not wait for SRCU readers before freeing the namespace struct. Multipath code iterates the head->list under srcu_read_lock() in nvme_find_path() and nvme_mpath_revalidate_paths(), so a concurrent reader can still hold a reference to ns when kfree(ns) runs. The normal removal path in nvme_ns_remove() correctly calls synchronize_srcu(&ns->head->srcu) after list_del_rcu() to wait for in-progress readers. Add the same grace period in the error path. Fixes: ed754e5deeb1 ("nvme: track shared namespaces") Cc: stable@vger.kernel.org Signed-off-by: Tristan Madani Reviewed-by: Sagi Grimberg Reviewed-by: John Garry Reviewed-by: Christoph Hellwig Signed-off-by: Keith Busch [ Adjusted patch context to account for missing last_path reference-counting code. ] Signed-off-by: Sasha Levin --- drivers/nvme/host/core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 0429ddda73be8..783758db4af78 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -3953,6 +3953,9 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid, if (list_empty(&ns->head->list)) list_del_init(&ns->head->entry); mutex_unlock(&ctrl->subsys->lock); + + /* guarantee not available in head->list */ + synchronize_srcu(&ns->head->srcu); nvme_put_ns_head(ns->head); out_cleanup_disk: blk_cleanup_disk(disk); -- 2.53.0