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 A3A9F331204; Wed, 21 Jan 2026 18:30:34 +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=1769020234; cv=none; b=hsj0yXT2luMAl/rBPbyl5KTZW991a9LuP4lHnvVN9USTY0f5U0u5zt3m+2dfmbsLSh5kImyoQ2148ulucjEVD+A/8JpdUov8dLYer3m6a0uWRSPW/KRY5+QvAKIZkf76TEwSGMOk3uBW+tg8oM5OHbpC14xOMrvPxIwGpc6al8I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769020234; c=relaxed/simple; bh=6Y4k5fY8EcGKOb5x9B3ydYifObXq3dH6vU19TZTajZs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bfYaEbTCp7YYH5Q1t6TQXj2hikBk41J/cTIGbMbyACDtkrluFKZ+66ifXlsEyPmh953pUDEs6MfESkY0zN3nAb4Lw370oIx3kvfKuzImz6WcKbVslMhlXBFEpdSmlFGMsUN/XhGWNvz0J53bSQhwdXlDs4iGzi0Y4eiy3J8hJzw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ftcs8LEI; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ftcs8LEI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 046DFC4CEF1; Wed, 21 Jan 2026 18:30:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1769020234; bh=6Y4k5fY8EcGKOb5x9B3ydYifObXq3dH6vU19TZTajZs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ftcs8LEI4LXmuk0plZgX6ZnaHpftVDJsgyPmK9wHYQwcbD3ZWuhw6v1HlzKvuTh2E AQ5TJNW0TaMtxp5Q3W7FWLnV0L2IQ1nqqVDA2Kqi+rWngg5a7ozR2LOEdH38JzdJX/ Du1BcNopLfjPUeeEhwZHLMi6BfsNFVVg/i5O5Syg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chaitanya Kulkarni , Nilay Shroff , Jens Axboe Subject: [PATCH 6.18 097/198] null_blk: fix kmemleak by releasing references to fault configfs items Date: Wed, 21 Jan 2026 19:15:25 +0100 Message-ID: <20260121181422.045419949@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260121181418.537774329@linuxfoundation.org> References: <20260121181418.537774329@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nilay Shroff commit 40b94ec7edbbb867c4e26a1a43d2b898f04b93c5 upstream. When CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION is enabled, the null-blk driver sets up fault injection support by creating the timeout_inject, requeue_inject, and init_hctx_fault_inject configfs items as children of the top-level nullbX configfs group. However, when the nullbX device is removed, the references taken to these fault-config configfs items are not released. As a result, kmemleak reports a memory leak, for example: unreferenced object 0xc00000021ff25c40 (size 32): comm "mkdir", pid 10665, jiffies 4322121578 hex dump (first 32 bytes): 69 6e 69 74 5f 68 63 74 78 5f 66 61 75 6c 74 5f init_hctx_fault_ 69 6e 6a 65 63 74 00 88 00 00 00 00 00 00 00 00 inject.......... backtrace (crc 1a018c86): __kmalloc_node_track_caller_noprof+0x494/0xbd8 kvasprintf+0x74/0xf4 config_item_set_name+0xf0/0x104 config_group_init_type_name+0x48/0xfc fault_config_init+0x48/0xf0 0xc0080000180559e4 configfs_mkdir+0x304/0x814 vfs_mkdir+0x49c/0x604 do_mkdirat+0x314/0x3d0 sys_mkdir+0xa0/0xd8 system_call_exception+0x1b0/0x4f0 system_call_vectored_common+0x15c/0x2ec Fix this by explicitly releasing the references to the fault-config configfs items when dropping the reference to the top-level nullbX configfs group. Cc: stable@vger.kernel.org Reviewed-by: Chaitanya Kulkarni Fixes: bb4c19e030f4 ("block: null_blk: make fault-injection dynamically configurable per device") Signed-off-by: Nilay Shroff Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/block/null_blk/main.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- a/drivers/block/null_blk/main.c +++ b/drivers/block/null_blk/main.c @@ -665,12 +665,22 @@ static void nullb_add_fault_config(struc configfs_add_default_group(&dev->init_hctx_fault_config.group, &dev->group); } +static void nullb_del_fault_config(struct nullb_device *dev) +{ + config_item_put(&dev->init_hctx_fault_config.group.cg_item); + config_item_put(&dev->requeue_config.group.cg_item); + config_item_put(&dev->timeout_config.group.cg_item); +} + #else static void nullb_add_fault_config(struct nullb_device *dev) { } +static void nullb_del_fault_config(struct nullb_device *dev) +{ +} #endif static struct @@ -702,7 +712,7 @@ nullb_group_drop_item(struct config_grou null_del_dev(dev->nullb); mutex_unlock(&lock); } - + nullb_del_fault_config(dev); config_item_put(item); }