From e873c74132f0c5f1452816cd9bb26208f0bba1e1 Mon Sep 17 00:00:00 2001 From: Shivank Garg Date: Sat, 22 Aug 2026 19:22:05 +0000 Subject: dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel() When dma_device_put() drops the last reference on chan->device->ref, dma_device_release() runs and may free the dma_device along with its channels. dma_chan_put() then still reads chan->device->owner via dma_chan_to_owner() for the trailing module_put(). KASAN catches it: slab-use-after-free in dma_chan_put+0x3e6/0x4c0 Read of size 8 by task insmod/6319 Freed by task 6319: kfree+0x225/0x470 dma_chan_put+0x395/0x4c0 dmaengine_put+0xf8/0x160 Cache the module owner in dma_chan_put() before the put so the trailing module_put() does not need chan->device. Fixes: 8ad342a86359 ("dmaengine: Add reference counting to dma_device struct") Suggested-by: Sashiko Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com Reviewed-by: Frank Li Reviewed-by: Logan Gunthorpe Signed-off-by: Shivank Garg Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com Signed-off-by: Vinod Koul --- drivers/crypto/caam/dpseci-debugfs.c | 60 ++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) create mode 100644 drivers/crypto/caam/dpseci-debugfs.c (limited to 'drivers/crypto/caam/dpseci-debugfs.c') diff --git a/drivers/crypto/caam/dpseci-debugfs.c b/drivers/crypto/caam/dpseci-debugfs.c new file mode 100644 index 000000000..020a9d8a8 --- /dev/null +++ b/drivers/crypto/caam/dpseci-debugfs.c @@ -0,0 +1,60 @@ +// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause) +/* Copyright 2019 NXP */ + +#include +#include +#include +#include "dpseci-debugfs.h" + +static int dpseci_dbg_fqs_show(struct seq_file *file, void *offset) +{ + struct dpaa2_caam_priv *priv = file->private; + u32 fqid, fcnt, bcnt; + int i, err; + + seq_printf(file, "FQ stats for %s:\n", dev_name(priv->dev)); + seq_printf(file, "%s%16s%16s\n", + "Rx-VFQID", + "Pending frames", + "Pending bytes"); + + for (i = 0; i < priv->num_pairs; i++) { + fqid = priv->rx_queue_attr[i].fqid; + err = dpaa2_io_query_fq_count(NULL, fqid, &fcnt, &bcnt); + if (err) + continue; + + seq_printf(file, "%5d%16u%16u\n", fqid, fcnt, bcnt); + } + + seq_printf(file, "%s%16s%16s\n", + "Tx-VFQID", + "Pending frames", + "Pending bytes"); + + for (i = 0; i < priv->num_pairs; i++) { + fqid = priv->tx_queue_attr[i].fqid; + err = dpaa2_io_query_fq_count(NULL, fqid, &fcnt, &bcnt); + if (err) + continue; + + seq_printf(file, "%5d%16u%16u\n", fqid, fcnt, bcnt); + } + + return 0; +} + +DEFINE_SHOW_ATTRIBUTE(dpseci_dbg_fqs); + +void dpaa2_dpseci_debugfs_init(struct dpaa2_caam_priv *priv) +{ + priv->dfs_root = debugfs_create_dir(dev_name(priv->dev), NULL); + + debugfs_create_file("fq_stats", 0444, priv->dfs_root, priv, + &dpseci_dbg_fqs_fops); +} + +void dpaa2_dpseci_debugfs_exit(struct dpaa2_caam_priv *priv) +{ + debugfs_remove_recursive(priv->dfs_root); +} -- cgit v1.3.1