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 57CFF399015; Tue, 21 Jul 2026 22:53:49 +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=1784674431; cv=none; b=oTtDq4UX5bOgkXYAuYYMaP0AmE6q+RQU76UFtj+b9FVDWOgR79YKuKYiQVRmDsC7s+vQLLC1iXgRR1WwzrTWpdorSYYZPANIkd7LgkooTQi4bgPbgrvfztcVI01snHl225WpnUE8fd6B3vIaUbXXgzXOx51EYsy/gukBGF7kmTo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784674431; c=relaxed/simple; bh=MurggVCtwziLxPYFF4wXpJkk0Yo2g+7ikqhkY7f26Ro=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=J+9p1/2djUMwrYOIHbnvthW0deeld9PSt0jkitg9M0OLs9S5rAsEskOQQD8oG2C9nYgqm9eU94repDmVfDfRC7uzrwZRbRKlIrw3EWJ4vLr5PWi2H2leDf3B2qlIs62dXTUfiGF5m9jOdwFJ5zBMXvuhG5EY7voZNGr1M+u7Ors= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ZaxZfx9K; 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="ZaxZfx9K" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BDF001F000E9; Tue, 21 Jul 2026 22:53:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784674429; bh=27ky9UJq8zGGBPaSZOqMYkjCtSt6B68QYhnUTrcF46c=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ZaxZfx9KdDVKdBeBGNispyY6zaj/K+VdrXp3026F6q7v8+jtY3+lRnlzbAAqI/pO8 FOR0kOn529YfRaZrGYWeHiFmIFAmnx7Zu2hMWmbmIrbaJym6dFYw/WCCA0Nx2e02Xo GOxpLmRYcA73Rfy1L9pyJtDMWjOZ20gzljdoDaRY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shitalkumar Gandhi , Simon Horman , Stefan Schmidt Subject: [PATCH 5.10 536/699] ieee802154: ca8210: fix pointer truncation in kfifo on 64-bit Date: Tue, 21 Jul 2026 17:24:55 +0200 Message-ID: <20260721152407.790294213@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: Shitalkumar Gandhi commit 6d7f7bcf225b2d566176bf6229dbd1252940cb3c upstream. ca8210_test_int_driver_write() and ca8210_test_int_user_read() exchange a kmalloc'd buffer pointer through a struct kfifo, but pass a literal '4' as the byte count to kfifo_in()/kfifo_out(). This is correct on 32-bit (pointer = 4 bytes), but on 64-bit only the low 4 bytes of the 8-byte pointer are written into the FIFO. The reader then reads back 4 bytes into an 8-byte local pointer variable, leaving the upper 4 bytes uninitialized stack data. The first dereference of the reconstructed pointer (fifo_buffer[1]) accesses an arbitrary kernel address and generally results in an oops. Use sizeof(fifo_buffer) so the byte count matches pointer width on every architecture. The driver has no architecture restriction in Kconfig, so any 64-bit build with CONFIG_IEEE802154_CA8210_DEBUGFS=y is exposed. Issue has been latent since the driver was added in 2017 because it is most commonly deployed on 32-bit MCUs. Found via a custom Coccinelle semantic patch hunting for short-byte kfifo I/O on byte-mode kfifos used to shuttle pointers. Fixes: ded845a781a5 ("ieee802154: Add CA8210 IEEE 802.15.4 device driver") Cc: stable@vger.kernel.org Signed-off-by: Shitalkumar Gandhi Reviewed-by: Simon Horman Link: https://lore.kernel.org/20260520105750.30144-1-shitalkumar.gandhi@cambiumnetworks.com Signed-off-by: Stefan Schmidt Signed-off-by: Greg Kroah-Hartman --- drivers/net/ieee802154/ca8210.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/net/ieee802154/ca8210.c +++ b/drivers/net/ieee802154/ca8210.c @@ -638,7 +638,7 @@ static int ca8210_test_int_driver_write( fifo_buffer = kmemdup(buf, len, GFP_KERNEL); if (!fifo_buffer) return -ENOMEM; - kfifo_in(&test->up_fifo, &fifo_buffer, 4); + kfifo_in(&test->up_fifo, &fifo_buffer, sizeof(fifo_buffer)); wake_up_interruptible(&priv->test.readq); return 0; @@ -2571,6 +2571,7 @@ static ssize_t ca8210_test_int_user_read struct ca8210_priv *priv = filp->private_data; unsigned char *fifo_buffer; unsigned long bytes_not_copied; + unsigned int copied; if (filp->f_flags & O_NONBLOCK) { /* Non-blocking mode */ @@ -2584,7 +2585,8 @@ static ssize_t ca8210_test_int_user_read ); } - if (kfifo_out(&priv->test.up_fifo, &fifo_buffer, 4) != 4) { + copied = kfifo_out(&priv->test.up_fifo, &fifo_buffer, sizeof(fifo_buffer)); + if (copied != sizeof(fifo_buffer)) { dev_err( &priv->spi->dev, "test_interface: Wrong number of elements popped from upstream fifo\n"