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 1BB423816F0; Wed, 21 Jan 2026 18:20:44 +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=1769019644; cv=none; b=glrNLejFT1MDlOD7YkDTO82VYdpoA7pPgONVTajtkHCj9s9FtHVDuoJyWSdf9YR9UXmlvP3BQFAiNxypmfEXOcUgRToTDrHY0GcZ5xPUNn/lEt9zpNqIzrrND80vfT1ntUYoOdFOpyiYrEkuZBC/NO/iU9+SmLvvPIA5OG+qsdc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769019644; c=relaxed/simple; bh=M158QqM/h0O5RKj1r+0Xijb5IykoVJPsQyUoEZvual4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lvPtRXGaVtdvGhxZdc6ErRcG+cwtcO3QZ7uMTw+Xlos3275BLhPDv8Ca81LLw1Qg1kaAaVMIAL4dYnw7D63TfkFNZnRXbgVFnlyyJPziubxSySqBtgTxsex8HBbfmFeZPNpuHbChxiPzMkVsSKFva0hwfteCTYi99uwbm9JE+7g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dUkFECKO; 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="dUkFECKO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 73F02C4CEF1; Wed, 21 Jan 2026 18:20:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1769019643; bh=M158QqM/h0O5RKj1r+0Xijb5IykoVJPsQyUoEZvual4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dUkFECKOwzQCJv3F0MoaU4yWowSyU8lcuUuabDpJ6gAF4fTG+2zgxVjCr3hfLqJJd dnuAmfQw9j7iQaoS+ZpbIJ/XU9HcsO7TCqlc3eojDtTYxnG4ot7rmZj3Rr+VoL2ltn PWPahlqBu+QaiH0vwBDsmwqfdmfnm5tHkqLbvXm0= 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 6.12 066/139] null_blk: fix kmemleak by releasing references to fault configfs items Date: Wed, 21 Jan 2026 19:15:14 +0100 Message-ID: <20260121181413.829909561@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260121181411.452263583@linuxfoundation.org> References: <20260121181411.452263583@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 6.12-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 @@ -655,12 +655,22 @@ 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 @@ -692,7 +702,7 @@ nullb_group_drop_item(struct config_grou null_del_dev(dev->nullb); mutex_unlock(&lock); } - + nullb_del_fault_config(dev); config_item_put(item); }