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 1C0B3443A9F; Tue, 21 Jul 2026 22:38:29 +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=1784673511; cv=none; b=UMTg7aL8fYpS7xFBMHcdnAYGHsX//v236+PK58dQElvqUxPlPzi/hq0hllYI8GyJRrTWCoP1vaFj7mL/De1wU/Edma8Bq+L5latVENCfue8ditt7TA4BIxTwBMFGa9ygVtn75b0wgHRaDf5AcoL1uiaE+zBWlsOkVCU1GbfEWqI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784673511; c=relaxed/simple; bh=0swpSv7GurC3W4JHlygrtJ6LCRiI/Q7TG1Tm5j+n9zc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LRHkKPunIZ8Bhzze0i6rfV6OlWHsS1cbCwJbLMTgWZt0Ic5sFTwpSXxuRwgRWdK+SEknTjOwzNLjbTJBGxFYLQKsVGmQCqPm6qVTXYnp+4/gPbAZes4wQtWQ7MN+gQSo4xWwRCGbnrc3ufQ9EhviHwFdzEztD0RlfKeHBMRggY0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Kphk1ns1; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Kphk1ns1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8341E1F000E9; Tue, 21 Jul 2026 22:38:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784673509; bh=LhSyNIokyZbzg+3wDhNSFd65/Qb6mBqAJp+Dihp+mbw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Kphk1ns1b6T2IbY2j6bFgMContDUTop1qkK5r1YM6hJ5FLWrgS/JazlNzvJMjwQP2 N0IkamusRMaPz0U6BdSYsxA/ZDoMxRYnfmW7mNWnQkwHCU5ofVHXzbUq/AM2K1fflH ldJ1gzxbfx/obdOH29hMRwiMS6uu2mk77F9RIQoc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Prathamesh Deshpande , Yishai Hadas , Leon Romanovsky , Sasha Levin Subject: [PATCH 5.10 190/699] RDMA/mlx5: Fix devx subscribe-event unwind NULL dereference Date: Tue, 21 Jul 2026 17:19:09 +0200 Message-ID: <20260721152359.984094974@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152355.667394603@linuxfoundation.org> References: <20260721152355.667394603@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Prathamesh Deshpande [ Upstream commit 43f8f7946814c8e5f464518246fdbc69b6e32326 ] MLX5_IB_METHOD_DEVX_SUBSCRIBE_EVENT() links event_sub into sub_list before initializing the fields used by the shared error path. If eventfd_ctx_fdget() then fails, the unwind path dereferences event_sub->ev_file in uverbs_uobject_put() and calls subscribe_event_xa_dealloc() with an unset xa_key_level1. subscribe_event_xa_alloc() creates the XA entry exactly once for a given key_level1, on the first occurrence of that key. The unwind path must therefore call subscribe_event_xa_dealloc() exactly once for it as well. Enforce that by adding devx_key_in_sub_list() and calling subscribe_event_xa_dealloc() only when the last matching pending entry is being cleaned up. Fixes: 759738537142 ("IB/mlx5: Enable subscription for device events over DEVX") Signed-off-by: Prathamesh Deshpande Link: https://patch.msgid.link/20260428224319.37682-1-prathameshdeshpande7@gmail.com Reviewed-by: Yishai Hadas Signed-off-by: Leon Romanovsky Signed-off-by: Sasha Levin --- drivers/infiniband/hw/mlx5/devx.c | 30 +++++++++++++++++++++++------- 1 file changed, 23 insertions(+), 7 deletions(-) diff --git a/drivers/infiniband/hw/mlx5/devx.c b/drivers/infiniband/hw/mlx5/devx.c index 679d85db26f4fd..361cd3c9780465 100644 --- a/drivers/infiniband/hw/mlx5/devx.c +++ b/drivers/infiniband/hw/mlx5/devx.c @@ -1746,6 +1746,17 @@ static int UVERBS_HANDLER(MLX5_IB_METHOD_DEVX_OBJ_ASYNC_QUERY)( return err; } +static bool devx_key_in_sub_list(struct list_head *list, u32 key_level1) +{ + struct devx_event_subscription *s; + + list_for_each_entry(s, list, event_list) + if (s->xa_key_level1 == key_level1) + return true; + + return false; +} + static void subscribe_event_xa_dealloc(struct mlx5_devx_event_table *devx_event_table, u32 key_level1, @@ -1995,10 +2006,17 @@ static int UVERBS_HANDLER(MLX5_IB_METHOD_DEVX_SUBSCRIBE_EVENT)( num_alloc_xa_entries++; event_sub = kzalloc(sizeof(*event_sub), GFP_KERNEL); if (!event_sub) { + if (!devx_key_in_sub_list(&sub_list, key_level1)) + subscribe_event_xa_dealloc(devx_event_table, + key_level1, + obj, + obj_id); err = -ENOMEM; goto err; } + event_sub->ev_file = ev_file; + event_sub->xa_key_level1 = key_level1; list_add_tail(&event_sub->event_list, &sub_list); uverbs_uobject_get(&ev_file->uobj); if (use_eventfd) { @@ -2013,9 +2031,6 @@ static int UVERBS_HANDLER(MLX5_IB_METHOD_DEVX_SUBSCRIBE_EVENT)( } event_sub->cookie = cookie; - event_sub->ev_file = ev_file; - /* May be needed upon cleanup the devx object/subscription */ - event_sub->xa_key_level1 = key_level1; event_sub->xa_key_level2 = obj_id; INIT_LIST_HEAD(&event_sub->obj_list); } @@ -2060,10 +2075,11 @@ static int UVERBS_HANDLER(MLX5_IB_METHOD_DEVX_SUBSCRIBE_EVENT)( list_for_each_entry_safe(event_sub, tmp_sub, &sub_list, event_list) { list_del(&event_sub->event_list); - subscribe_event_xa_dealloc(devx_event_table, - event_sub->xa_key_level1, - obj, - obj_id); + if (!devx_key_in_sub_list(&sub_list, event_sub->xa_key_level1)) + subscribe_event_xa_dealloc(devx_event_table, + event_sub->xa_key_level1, + obj, + obj_id); if (event_sub->eventfd) eventfd_ctx_put(event_sub->eventfd); -- 2.53.0